The battle over the timing of a second referendum on Scottish independence has intensified as a Conservative minister warned the SNP must wait up to 50 years before another vote could take place.
The intervention followed a letter sent by Boris Johnson to Nicola Sturgeon yesterday which insisted the result of the 2014 plebiscite must be respected.
The Scottish Government has argued Scotland must be "offered the right to choose its own future" ahead of the UK's impending departure from the European Union.
But the Prime Minister flatly refused SNP demands for a Section 30 order - the legal mechanism which would allow Holyrood to stage a vote on the constitution - and insisted "the UK Government will continue to to uphold the democratic decision of the Scottish people" taken in 2014.
Scotland Office minister Douglas Ross today denied the UK Government was running scared by refusing another vote but was instead offering a period of "calm" which would allow Holyrood to focus on domestic issues.
In an interview with BBC Good Morning Scotland, the MP Moray pointed to an answer given by then Deputy First Minister Nicola Sturgeon in a Scottish Parliament debate before the 2014 plebiscite - which she claimed was a "once in a generation" event.
Asked to define the timescale offered by Scottish Secretary Alister Jack, who said there should be no further referendum until "a generation or a lifetime" has passed, Mr Ross replied: "Nicola Sturgeon said a generation - and a generation is normally, I think, 30, 40, or 50 years."
Pressed for a more precise figure, Mr Ross continued: "A generation is stipulated around about that level. I don't think Nicola Sturgeon said, when she was coming up with a generation, what it actually was - and it's certainly not the six years since we last had a referendum."
Meanwhile, the Scottish Government has "many options" it could use to push for a second independence referendum if Boris Johnson continues to deny such a vote, a Holyrood minister has said.
Constitutional Relations Secretary Mike Russell spoke out after the PM rejected First Minister Nicola Sturgeon's demands for Holyrood to be given the power to stage a second ballot on Scotland's place in the UK.
The Tory leader claimed allowing such a vote would lead to continued "political stagnation" in Scotland, with the Government focused on making the case for independence instead of improving schools and hospitals.
Mr Russell, however, accused the Prime Minister of ignoring the wishes of Scots voters, who in last month's general election returned an increased number of SNP MPs.
After a campaign heavily focused on giving Scots the right to choose their country's future, Nicola Sturgeon's party won 47 of the 59 seats up for grabs north of the border.
Speaking on BBC Radio Scotland's Good Morning Scotland programme, Mr Russell said: "I think you can either have democracy or you can have dictatorship, you can't have both.
"If Boris Johnson wants to be a dictator that simply says 'other people's votes don't matter, Scotland's doesn't matter, Scotland isn't a nation', that is a decision which cannot hold in my view, because it goes so much against the views of the people of Scotland.
"Even those who are not in favour of independence, we know are in favour of saying it is right that if the people of Scotland vote for something they get their chance to choose. That is all this is about."