Nicola Sturgeon has warned Liz Truss against any attempt to “gerrymander the rules” on Scottish independence amid reports that ministers are planning measures to make securing a yes vote more difficult. An unnamed supporter of Truss, who is expected to become prime minister this week, suggested her government would introduce a requirement to demonstrate 60% support for another referendum before a new independence vote could be held. The source told the Sunday Times: “The SNP [Scottish National party] said after the 2014 referendum that they would not seek another one until polls consistently showed more than 60% of the public would vote to leave the UK. “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.” The paper also reported that ministers could raise the required voting threshold for independence to pass, from a simple voting majority to a majority of Scotland’s entire electorate. Sturgeon, who wants to hold a second independence referendum in October 2023, said fear of losing the vote was no justification for changing the rules. Speaking to Sky News’s Sophy Ridge on Sunday, the Scottish first minister said the reported amendment 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.” Sturgeon said the proposals were 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.” The first minister claimed there had “never been a positive case for the union made”. Boris Johnson indicated he would ignore any second referendum, prompting Sturgeon to ask the supreme court to rule on holding the vote without the UK government’s consent. The case will be heard next month with the verdict expected early next year. The Scottish National party MP Richard Thomson also criticised the reported plans to tinker with rules. He tweeted: “So … when the referendum that ‘isn’t going to happen’ happens, it’s to be with a fiddled franchise? That reeks of a few things from the UK government – arrogance, entitlement and contempt for starters, but certainly not of political confidence.” Support for independence in the polls peaked at 58% during the pandemic but that figure has slid in recent years. During the Conservative leadership race, Truss dismissed Sturgeon as an “attention seeker” whose calls for a second referendum “should be ignored”. In her Sky News interview, Sturgeon hit back at Truss. “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,” she said.