Andrea Leadsom, the Tory leadership candidate, has opened the door to another vote on Scottish independence, saying: “Never say never.”

At the press gallery lunch in Westminster, the former Commons Leader, who launched her campaign earlier today, stressed that she did not want another referendum but respected devolution.

“The reason I say 'never say never' is because I do not think that there should be another independence referendum in Scotland, I do not think it's in their interest, but on the other hand I am a big believer in devolution.

"So, what I just want to say is I am not going to stand here and utterly rule it out because that is disrespectful. But I would very strongly fight against a second referendum, which I don't think is in the interest of Scotland and it's definitely not in the interests of the UK.”

She added: "What we have to be doing is promote the strength of the UK working together far stronger, far more than we have done and I have a number of policy areas that I would use to try and make that happen."

In response, the SNP’s Joanna Cherry, who was also at the lunch, tweeted: “Fascinating answers from @andrealeadsom at press gallery lunch. Says she won’t rule out agreeing to #indyref2 if @ScotParl requests it because she has a great respect for devolved parliament. Looking forward to @ScotTories comments on this.”

One Scottish Conservative MP, when it was pointed out what Mrs Leadsom said, declared: “You are f*****g kidding me.”

Ross Thomson, the Tory MP for Aberdeen South, said: "Andrea is one of the loveliest, most charming people in Parliament and it is in her nature just not to say no to anyone.

"But from my perspective and the Scottish Conservatives, our number one clear ask is that any new prime minister will be just as robust in saying no to more referendums, whether that is on independence or Europe.

"We are so divided as a country right now a referendum will only exacerbate divisions further, I don't think any Scottish Conservative could back a candidate who won't be firm on saying no to indyref2. Never say never is just a bad Bond film."

He added: "Honestly, this is not something that we will equivocate on, we will always oppose a second independence referendum and we need a prime minister to reflect that."

Labour's Ian Murray said Mrs Leadsom's comments showed the Tories could not be trusted to protect Scotland’s place in the Union.

“The majority of people in Scotland don’t want a divisive second independence referendum and have rejected both the nationalism of the SNP and the Tories.

“With Boris Johnson threatening to make Scots workers pay towards tax cuts for the wealthiest people in England, this disgusting Tory leadership contest is putting the Union at risk," declared the MP for Edinburgh South.

“These Tories must stop putting their party before the country in their desperate scramble for the keys to Number Ten."

He added: “Ruth Davidson can’t remain silent on this; she must explain how she is going to stand up for the Union amidst these Tory attempts to create further division.”

Theresa May and David Mundell have consistently made clear that there is no way the UK Government would agree to facilitate a second vote on Scotland’s future before the next General Election, scheduled for May 2022.