Key Scottish Tory MP John Lamont comes out against Theresa May’s Brexit deal

Former Scottish Conservative chief whip in Holyrood John Lamont has said he will vote against Theresa May’s negotiated Brexit deal.

The withdrawal agreement, which is being debated in the Commons ahead of a proposed vote tomorrow, has been derided by both Brexiteers and Remainers within the Conservative party for being the worst of both worlds.

Lamont said he was "not a natural rebel", but the deal, which includes separate customs arrangements for Northern Irleand “threatens the integrity of the United Kingdom”.

The Berwickshire, Roxburgh & Selkirk MP is seen as an influential figure in the Scottish Conservatives, and his words will pile pressure on Scotland Secretary David Mundell, who reportedly said he would resign if Northern Ireland was given a closer relationship with the EU than the rest of the UK.

Mundell later said May’s deal was “the best one available”.

In a letter to constituents, Lamont said: “While some politicians had a knee-jerk reaction to this deal - I have been carefully considering the agreement in detail before coming to a view as to whether it delivers for my constituents and our nation.

“I have never doubted the Prime Minister’s commitment to deliver the best for this country. I don't think that any other leader could have negotiated a better deal.

“Even among those who do not support this deal, the vast majority of people recognise she has put her heart and soul into public service over the past few years. And she has had an almost impossible job to do.

“Reluctantly, I have come to the view that I cannot support the withdrawal agreement that has been negotiated with the EU, as it currently stands.”

Lamont said the agreement did not sufficiently protect against a situation when political priorities would change.

“It’s therefore really important that the words in the legally binding agreement deliver for Scotland and for the UK without having to rely on good will or a hope for the best attitude.”

He added: “This deal could mean that we retain some of the worst things about EU membership without being able to take advantage of the opportunities of Brexit. The UK could end up in an uncomfortable half-way house - having to follow EU rules without any influence or say over them. I have come to the conclusion that on balance, these are not risks I am prepared to take.”

Earlier Mundell told BBC Scotland he thought the integrity of the United Kingdom was threatened “by the uncertainty, by the division, by the chaos” that would follow a rejection of the deal.

There are reports Theresa May is now planning to delay the vote on her deal amid rumours it looks to be rejected.