Liz Truss has set herself on a collision course with Nicola Sturgeon just as she is expected to become the next prime minister.
Ms Sturgeon warned the leadership frontrunner will be a “disaster” in the top job if she governs in the same way she campaigned.
It comes amid reports UK ministers are considering a “referendum act” that would require more than half of Scotland’s entire electorate, rather than a simple majority, to vote to leave the Union.
If similar rules had been applied in 2014, when 45 per cent voted for Scottish independence and 55 per cent voted against with an 85% turnout, the Yes side would have required half a million extra votes to win.
Truss remains frontrunner
Ms Truss, the current foreign secretary, is the strong favourite in the two-person race to replace Boris Johnson as Conservative leader.
If she receives the backing of party members on Monday against former chancellor Rishi Sunak, she will travel to Balmoral on Tuesday to be appointed by the Queen.
An unnamed supporter of Ms Truss is quoted in the Sunday Times suggesting her government would introduce a requirement to demonstrate 60% support for another referendum before it could be held.
The source said: “In order to achieve independence it would not be unreasonable for the Yes side to demonstrate that it was the settled will of the Scottish people like in the 1997 devolution referendum where there was a three to one majority in favour of a Scottish parliament.”
They added that the government could act after the Supreme Court gives its verdict on plans to hold a referendum without Westminster approval.
‘Rewriting the rules of democracy’
Speaking to Sky News’s Sophy Ridge on Sunday, Ms Sturgeon said the reported referendum act would be “a changing of the basic rules of democracy that we have all abided by for our entire lifetimes and long before that”.
“Can you imagine the fear, fury, the literal foaming at the mouth that we would have had from the Conservative party if you suggested [new rules] for the Brexit referendum?” she said.
“Just because you fear losing a democratic contest, it’s not an excuse or doesn’t make it acceptable to rewrite the rules of democracy.”
The SNP leader described the proposals as an attempt to “gerrymander the rules”, adding: “That is a sign of fundamental weakness and a lack of confidence in her case for the union.”
During the Conservative leadership race, Ms Truss dismissed Scotland’s first minister as an “attention seeker” whose calls for a referendum “should be ignored”.
The pair exchanged barbs throughout the process, with Ms Sturgeon revealing the foreign secretary asked her how to get into Vogue when they met briefly last year.
FM will ‘try’ to get on with new leader
Ms Sturgeon said she will “try” to have a good relationship with Ms Truss if she is chosen by party members on Monday, as is expected.
“It’s obviously the case that Liz Truss and I don’t agree on very much politically,” she said.
“But I’m a firm believer in giving anybody who’s coming into the office of prime minister a chance to prove themselves – and I will certainly do my best to build a constructive working relationship with her.”
However, Ms Sturgeon added: “If she governs how she has campaigned over the summer, she will be a disaster – not just for Scotland but for all of the UK.
“But let’s hope that’s not the case, because this is a very serious time for the UK and it needs very serious and very purposeful leadership.”