THERESA May told her MPs to vote against the Common Market 2.0 in last night's indicative votes, because of fears it could weaken the case against Scottish independence, a BBC journalist has claimed.

Newsnight reporter Nicholas Watt said the Tory leader believed the proposal put forward by her former minister Nick Boles "would have destroyed main pro-UK argument in a Scottish independence referendum”.

The Common Market 2.0, or Norway plus plan, tabled by Boles and backed by MPs from all parties, would commit the Government to joining the European Free Trade Association and European Economic Area.

It would mean the UK remaining part of the EU single market, which in turn would mean freedom of movement.

It was defeated by 282 votes to 261, despite being supported by Labour and the SNP.

In a series of tweets, Watt said May had “ordered a particularly aggressive whipping operation against” the Common Market 2.0 plan.

The report claimed the Prime Minister believed it "could threaten integrity of UK".

An ally of Nick Boles tells he was so angry with Conservatives because Theresa May ordered a particularly aggressive whipping operation against his Common Market 2.0 proposal — Nicholas Watt (@nicholaswatt) April 1, 2019

He added: "PM feared that if UK stayed in single market through EFTA pillar of EEA that could increase support for Scottish independence.

“SNP would argue in an independence referendum: vote Yes to be fully in EU while maintaining full access to UK market because UK would be in single market.

“PM believes that at a stroke the Boles plan would have destroyed main pro-UK argument in a Scottish independence referendum: stay in UK as the only way to maintain full access to Scotland’s largest market in rest of UK”

That infuriated SNP MPs.

Pete Wishart claimed the Tories were willing to “make the UK poorer and more isolated to stick one to the SNP".

“Where we have been reasonable and conciliatory she has been gaming against independence,” he added.

Deidre Brock called it “disgraceful”.

So May heavily whips against the softer Brexit option tonight in part because she wants to keep trade threats dangling over the people of Scotland for next #Indyref - thought I was beyond being shocked by this place but no! disgraceful https://t.co/7dfCZWzv8j — Deidre Brock MP (@DeidreBrock) April 1, 2019

She tweeted: “So May heavily whips against the softer Brexit option tonight in part because she wants to keep trade threats dangling over the people of Scotland for next #Indyref - thought I was beyond being shocked by this place but no! disgraceful”