TORY cabinet ministers have privately conceded that “Westminster cannot keep saying no” to a second referendum on independence, the SNP’s Ian Blackford has claimed.

In an interview with The Herald, the Westminster party chief said Boris Johnson knows he will have to grant a Section 30 order in the future.

The SNP MP said: “I have had conversations with a number of Conservative ministers privately and they understand that this is a line which is going to be difficult to hold in the longer term.”

The National: Ian Blackford

Blackford refused to name the ministers but revealed they were at cabinet level.

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He added: “I don’t believe Boris Johnson sees that any differently to some of the other people I’m talking about.”

Blackford continued: “How many times do the people of Scotland have to vote for the SNP to give the Scottish Parliament a mandate to have an independence referendum?

“Is he really prepared to ignore a party that has got 80% of the seats from Scotland in this place and has won 45% of the vote?

“There is no government over the last couple of decades that has won with a share of the popular vote above 45% since 1966. It’s extraordinary.”

The SNP will also seek to make the case for independence internationally, the party chief said, saying they will be “building the case both for Scotland to be independent and for the right to have that independence referendum at home and abroad”.

The National: Nicola Sturgeon

Following the SNP’s victory at last month’s General Election, First Minister Nicola Sturgeon wrote to Johnson outlining the “democratic case” for another poll, and demanding the powers to allow a legally watertight vote be permanently devolved to the Scottish Parliament.

On Sunday, Scottish Secretary Alister Jack said there was no chance of a Section 30 order being granted while Sturgeon was First Minister or even during her lifetime.

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He told the BBC’s Sunday Politics programme that he’d advised Johnson to refuse the request: “Nicola Sturgeon has said she fully expects a rebuttal from the PM and my advice to him is to say that.”

He added: “Referendums are very divisive for our society and I think the time now is for us all to pull together as one United Kingdom, and go forward and take on the benefits that exist. Let’s see the benefits of Brexit. They have talked it down as being a disaster.

Jack told interviewer Gordon Brewer: “It’s absolutely the case that constitutional matters are reserved and must remain with the UK Parliament, in the same way as defence must remain, in the same way foreign policy must remain.

“It would be wrong for us to give the right to the Scottish Parliament to set referendums and the context and the timing for the simple reason that we would then be plunged into ‘neverendums’. That’s not good for us, that’s not good for the economy.”

The National: Alister Jack

A UK Government spokeswoman said: “We believe Nicola Sturgeon should keep her promise that the 2014 referendum would be a once in a generation event.”

Jack’s comments infuriated independence supporters.

Linda Fabiani accused him of giving up on the Smith Agreement. In a letter to the Tory minister, the MSP, who was one of the SNP’s representatives on the Smith Commission, said every party signed-up to the principle that the people of Scotland could choose independence.

The Commission agreed that “nothing in this report prevents Scotland becoming an independent country in the future should the people of Scotland so choose.”

Fabiani said: “This commitment is in black-and-white in the document agreed by your party and your government. “

She said the comments by Jack suggested the UK Government had “abandoned this key tenet of the Smith Commission. “

This, Fabiani added, “would be a gross betrayal of the promises made to the Scottish people”.