NICOLA Sturgeon has accused opponents of seeking to thwart the democratic wishes of Scots as she defended plans to step up the SNP's campaign for independence.

The First Minister claimed Labour, the Conservatives and Liberal Democrats were "frightened" of facing a second referendum.

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She hit back during the final televised leaders' debate of the election campaign after Kezia Dugdale, Ruth Davidson and Willie Rennie rounded on her pledge to hold a re-run of the 2014 poll if a series of opinion polls show a majority in favour of independence.

In a sign of how the constitution has overshadowed the election campaign the issue sparked the sharpest clashes between the leaders as both sides were cheered loudly by sections of the audience at Hopetoun House near South Queensferry.

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A poll yesterday put support for independence on 47 per cent, with 53 per cent of people wishing to remain part of the UK.

Scottish Labour leader Ms Dugdale accused the SNP leader of "trying to pull the wool over people's eyes" by failing to make a clear manifesto promise of a second referendum, while planning a fresh independence campaign.

Ruth Davidson, the Scots Tory leader, said Ms Sturgeon was "keeping this wound open" to the detriment of the economy.

The Herald:

Willie Rennie, the Scottish LibDem leader, won the biggest cheer of the night when he said: "I would go as far as to say it's anti-democratic."

But Ms Sturgeon countered: "What is it that gives them the right to stand in the way of the majority?

"No-one should fear the democratic wishes of the people of this country.

"What is it about the democratic will that people seem to find so frightening."

The clashes followed an interview with Ms Sturgeon in The Herald's sister paper, the Sunday Herald, in which she said she expected to lead Scotland to independence.

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She said the prospect of a second vote on the issue was now "more likely than not".

The party's manifesto says the Scottish Parliament should have "the right" to hold another referendum if there is "clear and sustained evidence" of majority support for independence, or if there is a "significant and material" change in circumstances, such as Scotland being taken out of the EU against its will.

Ms Sturgeon has already announced a summer independence campaign aimed at winning over the 55 per cent of Scots who voted No in 2014.

During the campaign she has said a referendum could be triggered if a number of polls show support for independence is "over 50 per cent".

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Speaking on the BBC's Andrew Marr show, she said she wanted a second referendum and for Scotland to be independent "sooner rather than later".

"But it's not just a decision for me, it's a decision for the majority of people in Scotland and there will only be a second referendum and there will certainly only be independence if a majority of people in Scotland want that," she added.

As the election battle entered its final 72 hours, a poll showed Scottish Labour opening a clear lead over the Scottish Conservatives in the race for second place.

The Panelbase survey put Labour six points ahead of the Tories in the constituency vote, at 23 per cent and 17 per cent respectively.

The SNP retained a commanding lead on 49 per cent, with support for the LibDems on 6 per cent and the Greens on 3 per cent.

In the all-important regional vote, backing for the SNP slipped three points to 44 per cent, with Labour on 22 per cent ahead of the Tories on 19 per cent.

The Liberal Democrats were on 4 per cent, behind the Greens on 6 per cent and only narrowly ahead of Ukip (3 per cent) and the left-wing alliance Rise (2 per cent).

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John Curtice, professor of politics at Strathclyde University, said: "While support for the Conservatives has largely held steady, it looks as though Labour may have been able to capture from the SNP some of those who were thinking of voting for Nicola Sturgeon but who are opposed to independence.

"Certainly the poll is a timely reminder to Ruth Davidson that her party's chances of coming second have always seemed to rest much more on how badly Labour might do rather than how far the Conservatives might advance – and maybe Labour will not do quite so badly after all."

He predicted the SNP would take 70 of Holyrood's 129 seats, with Labour winning 27, the Tories 24, Greens five and LibDems three on the basis of the poll findings.

The poll also found that in the event of the UK voting to leave the EU, 52 per cent said they would back independence compared to 48 per cent who would not.

The poll of 1074 voters was conducted between April 23 and 28.

It followed a number of polls suggesting the Conservatives were on course to achieve their goal of beating Labour to become Holyrood's main opposition party.