Sir Keir Starmer has confirmed Labour MPs will back a move to get a final vote on Theresa May’s Brexit Deal, if the House of Lords approves it next week.

Lords are pushing for the guarantee of a vote in Parliament on the final deal, to be written into the legislation that will allow Ms May to trigger Brexit talks.

Currently ministers want the Article 50 Bill passed unamended, but if they make no concession on the issue of a final deal, peers may force the matter to a vote next week, potentially inflicting an embarrassing defeat on Ms May in the Lords where her party is in a minority.

Sir Keir said on Tuesday: “If it’s won in the Lords then of course we’ll be supporting it.”

The Article 50 Bill was passed unamended through the Commons, with Sir Keir only managing to extract a verbal assurance from the Government that Parliament would be allowed a vote on the final deal Ms May secures.

However, there are two potential issues on which a coalition of Labour, Lib Dem, crossbench and rebel Tory Lords may win votes on amending the Bill this week.

Firstly, on attempting to get a guarantee for the rights of EU citizens living in Britain before the referendum, with a vote due on the issue on Wednesday.

Secondly, on the issue of giving Parliament a “meaningful vote” on Ms May’s Brexit deal, which is set to come to ahead on Tuesday March 7, at the next legislative stage in the Lords.

Any amendments passed by the Lords must them be approved by the Commons if they are to make it on to the statute book, meaning Sir Keir will have to convince around 15 Tory MPs to rebel before ministers actually have to rewrite their Bill.