NICOLA Sturgeon would do well to learn from the mistakes of David Cameron when planning another independence referendum.

Cameron caved in to party hardliners on Brexit when he did not need to, ignoring public opinion which was uninterested in a vote on membership of the European Union.

The former PM was motivated by a desire to keep his party together, rather than acting in the national self-interest. He compounded his blunder by holding back on criticising Boris Johnson during the referendum campaign. His legacy is in shreds.

Sturgeon stands at a similar crossroads to the one Cameron faced in 2013 when he announced an In/Out referendum. Only a very small proportion of voters support an early indyref and opinion polls almost uniformly show a majority is against secession. The First Minister is aware that Brexit is an unwelcome complication and realises her time would be better spent on the ‘why’ of independence, not the ‘when’.

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Even so, Sturgeon last week informed MSPs that she wanted a second indyref within two years. She also made a concession to her party’s Left by proposing changes to the SNP’s economic case - approved yesterday at their conference - to replace the pound with a new currency, a hugely risky move. Like Cameron, she was appeasing her own side.

Sturgeon knows the Conservative Government will not agree to a Section 30 order, the process by which Holyrood is temporarily given the power to hold a referendum. I would go so far as to say that the Tories will never agree to a re-run of the 2014 vote. Unionism is Ruth Davidson’s meal ticket and saying ‘No’ to Sturgeon provides the Scottish Tory leader with an electoral feast. The SNP will get nothing out of the Tories.

However, senior SNP figures believe the circumstances could exist for a Section 30 deal. Look at the small print of Sturgeon’s statement to MSPs last week. She wants to pass a framework bill - setting out the rules of a possible referendum - before the end of the year. She said the Tory Government “might soon be out of office”. She said she would seek agreement on a transfer of power at an “appropriate point”.

Sturgeon believes Theresa May’s chaotic Government will fall by the end of the year, to be replaced by a minority Labour administration led by Jeremy Corbyn. Consider the arithmetic. The Tories would block every left-wing reform proposed by Corbyn. The Lib Dems would not have the numbers to prop him up, even if they wanted to. The Democratic Unionist Party would seethe at the prospect of a Sinn Fein sympathiser like Corbyn being in Downing Street.

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Corbyn’s only option - unless a general election gave him an unlikely majority - would be to seek the support of the thirty-plus contingent of SNP MPs for the Budget and other legislation. Sturgeon’s party would be the kingmaker. Just as the DUP secured an extra £1bn from May, so too would the Nationalists demand a Section 30 deal from Corbyn.

It is not beyond the realms of possibility to imagine Corbyn agreeing to such a request. In 2017, he said he would allow a second referendum if the “Scottish Parliament and the Scottish people want it”. Asked last year what he would do if Sturgeon sought the power to hold another indyref, he replied: "We would obviously decide at the time." Corbyn has political red lines, but maintaining the integrity of the UK does not appear to be one of them.

If you look at politics through a Unionist Labour telescope, there is an obvious solution to this looming problem. Scottish Labour, not Corbyn, has been on the front line of the independence debate. It is party activists north of the border, not in London, who have been shouted at and dismissed as “red Tories”. Scottish Labour is much more hostile to indyref2 than Corbyn and his allies.

Richard Leonard could insist that Scottish Labour sets the policy on an independence referendum for the UK party. If Scottish Labour wanted to unequivocally rule out a Section 30 order, Corbyn should follow suit. He would also be obliged to stick to this script whenever he ventured to Scotland, rather than go off on one of his many indy riffs. The branch office would call the shots on this one.

The alternative is that Parliament could, to borrow an old phrase used by Alex Salmond, be “hung by a Scottish rope”. In this context, “Scottish” would mean SNP. Sturgeon may have made tactical mistakes last week, but her party is in line to have a dramatic effect on UK politics.