A split between Scottish Labour and the UK party is not the answer to the surge in support for the SNP, one of the candidates to replace Ed Miliband has said.

Liz Kendall, seen as part of the Blairite wing, also warned that Labour had "no God-given right to exist".

Her comments came as the polling expert John Curtice warned that Labour would need a 12.5 per cent lead over the Tories to win the next general election in 2020, if support for the SNP remained stable.

"Events north of the Border [show] the Blairite analysis of why Labour lost is frankly wholly inadequate," the Strathclyde University politics professor added.

At the weekend Andy Burnham, one of the favourites for the leadership on the left of the party, suggested that a separate Scottish Labour could be a solution.

Another Labour big beast, former Home Secretary Charles Clarke, has said that in his view the Scottish party should become an independent entity.

In a speech to journalists at Westminster, Ms Kendall appeared to contradict Mr Burnham, saying: "I'm not sure internal reorganisation of the Labour party is going to meet the challenge in Scotland.

"In the face of our wipeout in Scotland, and the growing sense of grievance in England, any simple or quick answers would be glib."

She added: "Let me make one thing clear, I don't believe that becoming ever more nationalist is the solution to the challenges we face.

"We are a United Kingdom. We have more that unites us than divides us, and we achieve more together than we do alone. Under my leadership the Labour Party will always make that case."

Ms Kendall, an MP for Leicester, also warned her party could suffer a similar fate in the north of England at the hands of Ukip as it has in Scotland.

She announced that she has asked another Labour frontbencher, Tristram Hunt, to lead for her on devolution.

Ms Kendall said her party had to respond to the challenges of nationalism and voter disillusionment.

She recommended more devolution of powers, including within England, to create "a new settlement for four countries in one union".

She also issued a passionate argument for the party to tack to the centre ground of British politics and try to win over voters who had backed the Tories.

And she hit out at some within Labour saying it was a "fantasy" that the party had lost because it was not left-wing enough.

In a dramatic shift in policy she said under her leadership Labour would support a two per cent defence spending commitment, something only Ukip and the DUP backed in the run up to May 7.

Meanwhile, the 56-strong group of SNP MPs have been described as "goons" by Sir Gerald Kaufman, the Father of the House of Commons.

The veteran Labour MP hit out following a row over the SNP's attempt to occupy a seat held by his colleague Dennis Skinner.

Sir Gerald described the move as "infantile", adding: "I don't know what they're trying to prove.

"It's all very well for them to try to sit in a block, but to move one of the longest-serving members of parliament out of a seat that he's occupied for decades, it's stupid."

"They're goons and if they go on like this instead of using their undoubted mandate from the Scottish people to be serious about issues on behalf of Scotland - which is what they've been elected to do - if they're going to play these infantile games, they will devalue themselves."

The SNP insists that it is only asking for the seats normally occupied by the third largest party.