Jeremy Corbyn will set out Labour’s plans for a post-Brexit customs union and a “new, strong relationship” with the single market in a major speech.
The Labour leader’s shift in position on a customs union with the European Union could leave Theresa May facing the prospect of Mr Corbyn’s MPs lining up with Tory rebels in an attempt to force a change in the Government’s approach.
In a speech in Coventry, Mr Corbyn will say existing single market rights, standards and protections would be accepted by Labour.
But it would negotiate protections and exemptions that could help workers and industry, such as changing state aid restrictions to allow governments to intervene to help struggling sectors.
Brexit Secretary David Davis said Mr Corbyn’s plans breached the promises he made at the general election and accused him of selling “snake oil”.
Setting out Labour’s approach, shadow international trade secretary Barry Gardiner said: “We have said that we recognise the benefits of the customs union as it stands and we are now saying that a customs union between the EU and the UK, where we together decide those third-party countries where we will have common tariffs and common quotas, is of benefit.”
Mr Gardiner, who has previously said a Turkish-style customs deal with the EU over customs would be a “disaster”, insisted Labour’s plans avoided some of the drawbacks of that approach by giving the UK a say over third countries’ access and the rules governing the arrangement.
“What we are talking about is a customs union in which we, as the UK, would be negotiating with the EU about those third parties, we would not be in the situation of being a rule taker.”
Tory rebels have backed a cross-party amendment to the Government’s Trade Bill calling for a customs union, and Labour’s policy shift could see them share common ground on the approach.
Asked whether a defeat over such a key part of the Prime Minister’s Brexit strategy could bring down the Government, Mr Gardiner told BBC Radio 4’s Today: “I don’t know what it would lead to. I don’t think anybody does.
“We do have to get it right here – leaving the EU was all about restoring sovereignty to the UK parliament.
“It is right that the UK parliament as the sovereign body in this country determines the policy that our government has for what will be the future arrangements with the rest of the world for the next 40 or 50 years.”
In his speech, Mr Corbyn will say Labour’s “jobs first” approach would include measures to stop employers being able to import cheap agency labour from abroad to undercut workers’ pay.
Mr Corbyn will say: “Every country that is geographically close to the EU without being an EU member state, whether it’s Turkey, Switzerland, or Norway, has some sort of close relationship to the EU, some more advantageous than others.
“Britain will need a bespoke relationship of its own. Labour would negotiate a new and strong relationship with the single market that includes full tariff-free access and a floor under existing rights, standards and protections.”
The Labour leader’s comments are set to upset some in the party who want the UK to remain in the single market.
But Mr Gardiner said British people who backed Brexit at the referendum “wanted to make sure we were regaining what they saw as our sovereignty, that we were not paying money into the budget of the European Union and that we had the ability to control our own borders.
“All of those things are things which we would not be able to do if we were part of the European Economic Area and therefore of the single market.”
Mr Corbyn will say leaving the European Union does not mean Britain is inevitably doomed.
The reality of Brexit is “more down-to-earth” than the naysayers and the fervent supporters claim, according to the Labour leader.
“The European Union is not the root of all our problems and leaving it will not solve all our problems,” he will say.
“Likewise, the EU is not the source of all enlightenment and leaving it does not inevitably spell doom for our country.”
He wrote: “The only way we can do this is if we have control over our own trade policy and are able to tailor agreements to our own needs, not those of 28 different countries. Being inside a customs union would make this impossible.
“These were points not lost on Labour at the last election when they promised to ‘work with global trading partners to develop ‘best-in-class’ free trade and investment agreements’.”
He added: “Labour may think they have stumbled across a simple solution to Brexit, but there is a lesson they are yet to learn: If it looks like snake oil, and it smells like snake oil, don’t expect it to make you feel better.”