The SNP could win all 59 Scottish seats in the General Election, new polling data has suggested.

The latest and final Ipsos MORI poll for STV News puts support for Nicola Sturgeon's party at 54%, up by two percentage points on the last poll, with Labour trailing on 20%, down from 24%.

Support for the Conservatives has increased by five points to 17% while the Liberal Democrats are on 5%, up one point, the Greens are on 2%, down by two points, Ukip are polling at 1%, with support for other parties also at 1%.

Using these figures, the Electoral Calculus website predicts that the SNP would take all 59 seats in Scotland.

Ipsos MORI questioned 1,071 people between April 22 and 27 on how they would vote if there were a Westminster General Election tomorrow.

It is the latest poll to show a record level of support for nationalists after a survey by TNS published on Monday put the SNP on 54%.

It recorded support for Labour at 22%, the Tories at 13%, Lib Dems at 6% and the Greens and Ukip both on 2%.

Using the Electoral Calculus seat predictor, the TNS results put the SNP on 57 seats, with one each for Labour and the Lib Dems.

Another TNS poll published today in the Herald newspaper shows record levels of support for Ms Sturgeon across the country.

The snapshot of 1,200 adults in Scotland, England and Wales shows the First Minister has the highest approval rating of the party leaders.

The poll gave Ms Sturgeon a Britain-wide net approval rating of plus 33, a record for TNS.

She is followed by Nigel Farage on plus 12, David Cameron on plus 7, Ed Miliband on minus 8, and Nick Clegg on minus 22.

Ms Sturgeon is top of the polling in every part of the country, leading on plus 30 in north-east England, plus 38 in Wales and the West Country and plus 33 in Greater London.

In Scotland, her approval rating surges to plus 55, where she is the only leader with a positive net rating.

Commenting on the Ipsos MORI poll, SNP deputy leader Stewart Hosie said: "This record poll shows that our positive campaign to make Scotland stronger at Westminster by electing a team of SNP MPs is gaining momentum, but we are working hard for every vote because we take absolutely nothing for granted.

"More anti-Tory MPs than Tory MPs in the House of Commons means that we can lock David Cameron out of Downing Street - so voting SNP delivers a strong voice for Scotland and progressive policies for the whole UK, including an end to cuts."

The Ipsos MORI poll also indicated that 80% of Scots are certain to vote, five points down on the turnout at the referendum on Scottish independence last September and 16 points up on the percentage of Scots that voted in the last general election in 2010 (64%).

Reacting to the increase in support for the Tories, now just three percentage points behind Labour, the party's deputy leader Jackson Carlaw said: "With a week to go before we vote, this poll shows that the Scottish Conservatives are the pro-UK party which has won the arguments in the campaign and is now gaining support.

"People in Scotland have had a good look at Labour and the Lib Dems over the last five weeks. They appear to have been left unimpressed and have now decided against them.

"If people want a strong Unionist party that can take on the SNP, they have to vote for it. They have to vote Scottish Conservative."

Scottish Labour deputy leader Kezia Dugdale said: "The choice facing Scots next week is clear. We can vote for Labour to take the road to a fairer and better nation for working-class families.

"Or we can back the SNP and go down the road to another referendum. When there is so much inequality in our country, the priority right now just can't be another drawn-out referendum campaign.

"A vote for anyone other than Labour makes it more likely the Tories will be the largest party across the UK and that David Cameron will walk back into Downing Street."