Nicola Sturgeon attacked Labour’s attempt to make a second independence referendum an issue in the General Election as a “desperate” act from “a party in its death throes”.

The dismissal came as she launched the SNP’s final advert of the election campaign yesterday and embarked on a helicopter tour of a dozen target constituencies.

The last campaign poster shows some of the green seats in the House of Commons turned into red tartan and proclaims: “More SNP seats. More power for Scotland.”

The First Minister was mobbed by supporters as she hit the campaign trail in the Leith area of Edinburgh to unveil the advert yesterday and said the message behind her party’s campaign was straightforward.

She said: “If you want Scotland’s voice to be louder, if you want the Westminster system to work better for people in Scotland and people across the UK then you’ve got to come out and vote SNP because the more seats we have in the House of Commons the more power Scotland has.”

During the final First Minister’s Questions before the General Election, Labour’s Kezia Dugdale called on the SNP leader to repeat her assertion that last year’s referendum was a “once-in-a-lifetime opportunity”.

The First Minister said that “nobody was proposing” a second independence referendum and if the people of Scotland wanted a referendum to be a “once-in-a-lifetime opportunity”, that is what it would be.

She said the move to make it an issue in the General Election was a “desperate” act from a dying party.

“This is desperate, last-throw-of-the-dice stuff from Scottish Labour. Talk about a party in its death throes.

“The desperate scaremongering over full fiscal autonomy clearly hasn’t made any impact, although actually that’s not true, it has made an impact on the polls – the SNP poll rating has gone up,” she said.

Continuing with the referendum question, the Lib Dems’ Willie Rennie challenged the First Minister to rule out a vote in the next term of the Scottish Parliament.

He said: “This is the neverendum that we warned about. We saw the consequences of the whole machinery of government being focused on the referendum for the last three years.”

But Sturgeon fought back saying that the people in Scotland were in charge.

She added: “What people are saying to me on the streets and doorsteps of Scotland is not about another referendum, their concerns are about the cuts that his [Rennie’s] party, hand in hand with the Tories, have imposed over the past five years.”

As the final weekend of election campaigning approaches the First Minister embarked on a tour of a dozen key seats across Scotland.

Following the last First Minister’s Questions at Holyrood she left Edinburgh by helicopter for Galashiels in the Borders.

Afterwards she visited Moffat, while in the coming days her tour will take in East Lothian, Dundee, St Andrews, Stonehaven, Inverness, Portree, Glasgow and Largs before ending in Dumfries on Monday.

Her visit to the target seats comes as polls show record levels of support for the SNP and as the Scottish Sun declared its backing for the party.

An Ipsos Mori poll for STV News found support for the SNP at 54 per cent while Scottish Labour had slipped to 20 per cent.

The SNP leader said she would continue to work hard for every vote.

“There’s now only one week to go until the election and the extent of the opportunity in Scotland’s grasp is becoming clearer by the day,” she said.

“But while the polls are welcome, polls don’t win elections – hard work, commitment and positive ideas do.

“The SNP will use our influence at Westminster to make sure every part of Scotland has a strong voice in the

House of Commons, put an end to the cuts and advance progressive politics for everyone in the UK – but we can only do that with the support of people in communities across Scotland next Thursday.

“If Scotland comes together on polling day and elects a big team of SNP MPs, we can ensure Scotland speaks loudly and clearly at Westminster – with a voice that simply can’t be ignored by the establishment parties.

“The prospect of a strong team of SNP MPs holding unprecedented power and influence for Scotland at Westminster is now within touching distance – today I’m asking people [to] unite with us and grab this historic opportunity with both hands.”