Theresa May will have formal meetings with the leaders of all the G7 countries at the group’s summit in Canada – except US President Donald Trump.
The US leader is at odds with the other six countries in the group – the UK, Canada, Germany, France, Italy and Japan – over his protectionist tariffs on steel and aluminium imports.
Mr Trump is not expected to spend as long at the summit in Charlevoix, Quebec as other leaders, leaving little time for formal bilateral meetings in front of the world’s press.
But Mrs May is expected to have informal talks with the US president and will seek to use the summit to avert a damaging trade war, insisting she wants a “proportionate” response from the European Union to the US tariffs.
The Prime Minister told reporters on the plane to the summit in Quebec: “I made my views clear on the steel and aluminium tariffs that President Trump has announced, I have done that directly to him.
“My most recent conversation with him was on Monday this week.
“We disagree with these, we think they’re unjustified.
“Obviously the European Union will be responding.
“We want to ensure, and we’re working with others in the European Union to ensure, that this response is proportionate, that it is within the WTO rules.
“As the UK, we want to be a great champion of free trade around the world and that’s what we will continue to be.
“I will continue to put the argument for the importance of those trade relationships around the world and I’ll be doing that here at the G7 as I have done elsewhere and will continue to do elsewhere.”
The meeting of G7 leaders follows a stormy gathering of the countries’ finance ministers earlier this month where the US was left isolated because of the rift caused by the refusal to exempt allies from the 25% tariff on steel imports and the 10% duty on aluminium.
The European Commission has confirmed it intends to hit back with retaliatory tariffs from July on US imports ranging from jeans to bourbon whiskey.
Despite the threat of tit-for-tat trade reprisals threatening to overshadow the meeting, Mrs May will use the summit to call on internet giants to do more to remove content showing violence against women.
The Prime Minister will tell her counterparts they must work with the tech industry to make the internet a place where women are not subjected to rape threats, harassment or cyberstalking.
The Prime Minister will hope the gathering in the picturesque Charlevoix region of Quebec on Friday and Saturday offers a chance to leave her domestic Brexit difficulties behind.
She will encourage companies to do more to quickly identify and take down online content promoting or depicting violence against women and girls, including illegal violent pornography and rape threats on social media platforms.
Research by Amnesty International UK found one in five women had suffered online abuse or harassment.
Mrs May will say: “We know that technology plays a crucial part in advancing gender equality and empowering women and girls, but these benefits are being undermined by vile forms of online violence, abuse and harassment.
“What is illegal offline is illegal online and I am calling on world leaders to take serious action to deal with this, just like we are doing in the UK with our commitment to legislate on online harms such as cyber-stalking and harassment.
“Online violence against women and girls should not be separated from offline violence and the technology companies who are making welcome progress in banning and removing extremist content must use the same methods to prioritise tackling this unacceptable and deeply worrying rising trend.”
The Prime Minister’s comments will come at a G7 session discussing empowering and supporting women and girls around the world.
Mrs May will pledge £187 million of new UK funding to help over 400,000 girls in developing countries receive 12 years of quality education.
The Prime Minister will say: “I am a passionate advocate of improving education for girls around the world.
“It is the right thing to do and it is in the global interest.
“That’s why the UK is leading the way in changing views, opening up opportunities for girls and bringing parity to the classroom.”
Mrs May will also seek to maintain the alliance she has forged over Russia following the poisoning of former spy Sergei Skripal and his daughter Yulia in Salisbury.
New Italian Prime Minister Giuseppe Conte has broken ranks with other Western leaders by calling for an end to sanctions on Russia and promising to advocate for a thaw in the relationship with Moscow.
“We are very clear and will be, should the subject arise, that sanctions on Russia absolutely need to remain in place,” a senior UK Government source said.
Mrs May is scheduled to have a meeting with Mr Conte on Saturday after talks with Canada’s Justin Trudeau, France’s Emmanuel Macron, Germany’s Angela Merkel and Japan’s Shinzo Abe on Friday.