JEREMY CORBYN wrote to Theresa May to set out five demands for her to get Labour’s support for a Brexit deal, in advance of the Prime Minister’s return to Brussels for talks today.

The Labour leader calls for a “permanent and comprehensive UK-wide customs union,” and close alignment with the single market.

Other demands are “dynamic alignment on rights and protections” to those of the EU, as well as commitments on participation in EU agencies and funding programmes, and “unambiguous agreements” on the detail of security arrangements.

He told the PM that seeking modifications to the Irish backstop proposals would not be enough to win widespread backing and that she must change some of her red lines.

In Brussels, Ms May was told again by the EU that it will not reopen the Withdrawal Agreement to make any changes to the controversial backstop, which could see Britain tied for years to EU regulations after any transition period if a new relationship cannot be agreed.

A Downing Street spokeswoman confirmed that Mr Corbyn’s letter had been received, and that a reply would be sent “in due course.”

She added: “Our positions on many of the issues in the letter are well-known. Our position on the backstop has not changed.”

Shadow international trade secretary Barry Gardiner defended the shift in policy away from the six tests Labour originally set for a Brexit deal, saying the offer was made “in a spirit of co-operation and compromise.” Unlike the six tests, Labour is not demanding the “exact same benefits” of the single market and customs union.