Nicola Sturgeon has warned Conservative leadership hopefuls not to block a second independence referendum after she published legislation paving the way for another vote.

The First Minister said most Scots, whether they supported independence or not, would “not accept being told by a Tory PM that we are not ‘allowed’ to choose our own future”.

It followed three of the 11 declared candidates vying to replace Theresa May swiftly ruling out giving Holyrood the missing power it would need to hold another vote on the constitution.

Home Secretary Sajid Javid, International Development Secretary Rory Stewart and Brexit Minister James Cleverly all said they would oppose any attempt to overturn the No vote of 2014.

With Scottish Tory leader Ruth Davidson making opposition to Indyref2 a precondition of her support in the leadership race, all the other candidates are expected to follow suit.

The row highlighted the critical flaw in the Scottish Government’s 168-page Referendums (Scotland) Bill, which is intended to create a generic framework for the conduct of votes, including campaign rules, donations, criminal offences and the franchise. 

As it stands, the legislation only covers issues within Holyrood’s devolved competence. 

To serve as the basis for a referendum on independence, it would require a transfer of extra power from Westminster under a Section 30 order.

Without it, an independence referendum would be open to legal challenge and stall in court.

Ms Sturgeon has said she wants to hold Indyref2 in the second half of next year, but there is  little prospect of a UK Government, under any prime minister, granting a Section 30 order by then and adding uncertainty over the Union to an in-tray already bursting with Brexit.

The First Minister’s bill is essentially a campaign tool for the 2021 Holyrood election, allowing her to cite the UK’s refusal as more evidence of Scotland’s wishes being ignored.

She said: “An independence referendum within this parliamentary term will give Scotland the opportunity to choose to be an independent European nation – rather than have a Brexit future imposed upon us.

“We will seek agreement to a transfer of power at an appropriate point to enable an independence referendum that is beyond challenge to be held later in this Parliament.

“It is essential the UK Government recognises that it would be a democratic outrage if it seeks to block such a referendum – indeed, any such stance would, in my view, prove to be utterly unsustainable.”

Brexit Secretary Michael Russell told MSPs a no-deal Brexit could see “an accelerated timetable” on an independence vote.

He said: “The Tories are heading for a no-deal Brexit, and some positively welcome that disastrous direction of travel.

“A Boris Johnson premiership is no longer a bad joke; it is a frightening possibility.

 “Substitute Raab, or Leadsom or Gove or Hancock, or McVey, or any of the others, for Johnson and the situation is no better.

“Most are heading, with pleasure, to the cliff edge, but Scotland must not be forced to go with them against our will.”

The Scottish Tories said the bill was a “Trojan horse” designed to create the framework for a Catalan-style illegal referendum, despite Ms Sturgeon repeatedly ruling this out.

Tory MSP Adam Tomkins said: “In reality, this is Nicola Sturgeon laying the ground for a ‘wildcat’ second referendum on independence.

“It’s a power grab on an industrial scale.

“It’s not about the democracy of letting people decide in a lawful referendum – it’s about the diktat of an independence-obsessed First Minister.”

Labour leader Richard Leonard said the SNP’s “obsession with the creation of a separate Scottish state” was a distraction from the “real issues” Holyrood was meant to address.

Scottish LibDem leader Willie Rennie said “constitutional confusion” was holding the country back from fixing problems in health and education.

He said: “The SNP have learned absolutely nothing from the lessons of Brexit. Breaking up long term economic partnerships leads to nothing but chaos and economic upheaval.”

However Green MSP Patrick Harvie welcomed the bill, adding: “We respect the fact that some people don’t want to see this debate even take place. But those who oppose independence should come forward with positive alternatives.

“The status quo is broken and we should not ask Scotland to face a chaotic Brexit and a hard-right Prime Minister, without the power to make our own choices about our own future.”

There was also a row after it emerged the bill would allow the Scottish Government to pose a Yes/No question in an independence referendum – if it had the power to hold one – without consulting the Electoral Commission on its validity.

The legislation said the watchdog need not be consulted if it had previously expressed a view.

The commission approved Yes/No for the 2014 referendum, but later changed its mind at the EU referendum, backing a Remain/Leave format instead as Yes/No was seen to advantage Yes.Amid fears the Indyref2 question could be based on an outdated opinion, the Commission said it would want to review any such question, even if it was the same one used in 2014.

“This would ensure that the Scottish Parliament’s scrutiny of any referendum bill is informed by any relevant or new factors,” a spokeswoman said.

The Tories claimed the SNP were trying to “evade scrutiny” on a possible question, which the Scottish Government denied.