Liz Truss and Rishi Sunak have spent the summer trying to woo Conservative voters while touring the country and taking part in hustings.
The pair have repeatedly clashed on plans to tackle the cost-of-living crisis and how to run the country.
Now, with only a few days left before the result of the contest is announced, one of them will have to turn those plans into reality.
So where do they stand on key issues?
– Energy bills and the cost of living
Rishi Sunak: The former chancellor has said that protecting people from rising energy bills will be his “immediate priority” as prime minister.
Having pitched himself as the fiscally conservative candidate, he has criticised his rival’s tax-cutting plans as “comforting fairytales”.
He has promised to “deliver tax cuts that drive growth”, but to do so in a “way that’s responsible”, while branding plans by Ms Truss as “morally wrong” for passing debt on to the next generation.
Mr Sunak has also pledged to temporarily scrap VAT on energy bills from October, saving households around £160 at a cost to the Exchequer of around £4.3 billion.
He has said he would look at soaring energy costs for businesses, as well as stressing that he would provide “direct financial assistance” to those on the lowest incomes and pensioners.
At the start of August, he also promised the “biggest income tax cut since Margaret Thatcher’s government”.
He vowed to take 4p off income tax within seven years if he becomes prime minister.
Cutting the basic rate from 20p in the pound to 16p would amount to a 20% tax reduction, the largest cut to income tax in 30 years.
At a hustings in London on Wednesday, she also claimed there will be no new taxes or energy rationing if she becomes prime minister.
Throughout the campaign she has pledged to “start cutting taxes from day one” with a new Budget and Spending Review that would reverse April’s rise in National Insurance and next year’s corporation tax increase from 19% to 25%.
She also said she would “simplify” taxes and ensure people are not penalised for caring for children or relatives.
She has not fully explained how she would fund the £30 billion in tax cuts she has promised, but said they “can be paid for within the existing fiscal envelope”.
She has committed to spreading the country’s Covid debt over a longer period of time, while insisting curbing taxes will boost growth.
Ms Truss has also unveiled plans to turn brownfield sites and other locations into “investment zones”, dubbed “full-fat freeports”.
Rishi Sunak: He has reiterated his support for the Government’s controversial Rwanda asylum policy, saying he would do “whatever it takes” to get it up and running.
The former chancellor has also unveiled a 10-point plan which includes the promise of a narrower definition of who qualifies for asylum compared with that offered by the European Convention on Human Rights, with enhanced powers to detain, tag and monitor illegal migrants.
He promised to give Parliament control over who comes to the UK by creating an annual cap on the number of refugees accepted each year, albeit one that can be changed in the case of sudden emergencies.
Liz Truss: The Foreign Secretary also supports the Rwanda policy and has said that under her leadership it could be extended further, with partnerships with more countries and further return and resettlement agreements.
She has also said she will increase Border Force staff levels from 9,000 to 10,800 and double the Border Force Maritime staffing levels, while also bringing forward a strengthened UK Bill of Rights to provide a “sound legal basis” to tackle illegal migration.
– Identity politics
Rishi Sunak: The former chancellor has pledged a “manifesto for women’s rights”, including opposing biological men being allowed to compete against women in sport, and guidance for schools on how they teach issues of sex and gender.
He has also vowed to review the 2010 Equality Act to stop the “woke nonsense” it has allowed to “permeate public life”.
He wants to preserve gendered words such as “woman” or “mother” by ensuring sex means biological sex in the legislation, and clarify that gender self-identification does not have legal force.
He has promised to protect free speech by amending the Public Sector Equality Duty, which requires public bodies to consider discrimination.
This would be to ensure organisations “are open and welcoming” to people with differing political opinions and religious and philosophical world views, “putting a stop to practices such as no-platforming”, his campaign said.
Liz Truss: She has previously shelved plans for an overhaul of gender recognition rules to make it easier for trans people to change their legal gender.
But she has also spoken out in favour of single-sex spaces, telling a Conservative Party hustings audience that she backs a policy which guarantees that schoolgirls can go to a toilet in a safe environment.
“I believe in treating transgender people with respect, I think that’s important, but we should not confuse that with being clear in our language,” the Foreign Secretary told a hustings event.
– Brexit and Europe
The former chancellor backs the Northern Ireland Protocol Bill and said recently: “Northern Ireland’s economy is being dragged out of the orbit of the UK, and that’s wrong, and as prime minister I want to fix that.”
He has also said that as prime minister he would deliver a “better UK alternative” to the EU’s Horizon funding programme, accusing the EU of “playing politics” on UK access to the scheme.
Liz Truss: The Foreign Secretary voted Remain but has since embraced Brexit and scooped up the backing of staunch Brexiteers in the party. She also helped to push through the Northern Ireland Protocol Bill which critics say breaks international law.
She has vowed to review all EU laws retained after Brexit by the end of next year in a “red tape bonfire” if she becomes prime minister, and to scrap or replace those that are deemed to hinder UK growth.
She has reportedly said she would seek to reform the European Convention on Human Rights but would be “prepared to leave” it.
She has vowed to replace EU law which restricts the development of farming infrastructure and technology, including agricultural drone use and precision breeding technologies.
She also promised to tackle the labour shortages in farming, partly caused by post-Brexit freedom of movement restrictions, with a short-term expansion to the seasonal workers scheme.
– Law and order
Rishi Sunak: Criminals who refuse to attend court for their sentencing would face longer terms behind bars, said Mr Sunak.
Police would be ordered to take tougher action to tackle “grooming gangs” and officers “must be fully focused on fighting actual crime in people’s neighbourhoods, and not policing bad jokes on Twitter”.
He has also pledged to expand police powers to tackle anti-social behaviour, and crack down on graffiti and littering.
Liz Truss: She has said she would order police to go “back to basics” and cut homicide, serious violence and neighbourhood crime by 20% by 2024 rather than investigating “Twitter rows and hurt feelings”, with league tables showing forces’ performances.
She also said she would conduct a review into how to tackle anti-social behaviour and how to tackle the causes behind it.
Liz Truss:The Foreign Secretary has pledged to increase defence spending to 3% of GDP by 2030 and strengthen the intelligence services. She said the Government’s current plan to cut the size of the Army to 72,500 in 2025 is “up for review”. More recently she said she would declassify more intelligence to expose “Putin’s playbook”.
Rishi Sunak: He has promised a “vaccines-style” taskforce to tackle NHS backlogs, saying dealing with the issue is one of his top priorities.
He proposes to expand the network of specialist surgical centres and community diagnostics hubs in order to eliminate one-year NHS waiting times six months earlier than planned, by September 2024, and to get overall numbers falling by next year.
The former chancellor also set out a plan to tackle missed appointments in the NHS to free up capacity.
Liz Truss: She agrees on the urgent need to deal with care backlogs, promising to install a “strong” health secretary to solve the issue.
She has also said she is “completely committed” to current Government promises on NHS spending, despite her plans for tax cuts.
She has also spoken about changing a “culture” of waste in the NHS.
– Climate change and net zero
Rishi Sunak: The former chancellor is committed to reaching net zero emissions by 2050.
He has pledged to keep the ban on building new onshore wind farms, but wants to introduce a legal target to make Britain energy self-sufficient by 2045 by overseeing a massive expansion in offshore turbines.
He also promised urgent action to drive up domestic energy supply with the creation of a new energy security taskforce and deregulation in the North Sea to allow gas production to increase over the winter.
Liz Truss:The Foreign Secretary backs the net zero push, but would pause green levies on domestic energy bills, which could damage the target.
She has said there is a strong case for lifting the ban on fracking and wants to move away from the EU’s habitat directive in favour of a stronger British biodiversity target.
– Foreign affairs
Rishi Sunak: He has promised to close all 30 of Beijing’s Confucius Institutes in the UK and “kick the CCP (Chinese Communist Party) out of our universities”, declaring China “the biggest-long term threat to Britain”.
Liz Truss: Her campaign says she “helped lead the international response to increased Chinese aggression” as Foreign Secretary and “this will only continue when she becomes prime minister”.
– Housing and infrastructure
Rishi Sunak: He has vowed to improve housing stock and energy efficiency.
The former chancellor wants to scrap EU Solvency II rules to help investors put money into infrastructure assets.
He has also pledged to slash the number of empty shops in Britain’s high streets by removing hurdles for those properties to be quickly converted into new businesses or cafes.
He would seek to reduce regulations around farmers’ markets, make local authorities assess social value when considering the location of public services, and protect access to cash machines. He has also pledged to ban new smart motorways and stop the “war” on motorists.
Liz Truss: The Foreign Secretary would scrap what she calls “Stalinist” housing targets in favour of tax cuts and deregulation. She has also come out in opposition to smart motorways.
Rishi Sunak:The former chancellor has said he backs the “return” of grammar schools, which initially prompted questions over whether he wants to overturn the ban on new institutions imposed by Labour more than 20 years ago.
However, it is understood he supports the expansion of existing grammar schools in local areas.
Liz Truss: She has pitched herself as the “education prime minister” with a six-point plan that includes replacing failing academies with “a new wave of free schools” and improving maths and literacy standards.
She has said she would end the ban on new grammar schools.
Scotland and the Union
Rishi Sunak: He has said the Union is “by consent”, but also told a hustings in Perth that he does not think “now or any time in the near future” is the time to consider another vote on Scottish independence.
Liz Truss: She said she would become the Minister for the Union, promising to put it at the “heart” of everything her Government does. She told Tory members in Perth that she would “not allow” another vote on independence if she was elected as prime minister on September 5.
Covid-19 and lockdowns
Rishi Sunak: He has claimed that independent experts were given too much power during the pandemic, with concerns about the economic and social impacts of lockdowns not properly considered.
Liz Truss: She said she questioned lockdown policy during the pandemic, and argued on reflection “we did do too much”. She also indicated that she would “never impose a lockdown” as prime minister.