Nicola Sturgeon has said people across the UK will not forgive Ed Miliband if he turns down the chance to lock the Conservatives out of Downing Street.
Speaking on the campaign trail in Ayrshire today, Sturgeon said: "If there is an anti-Tory majority in the House of Commons after the election, then the only way David Cameron gets back into Downing Street is if Ed Miliband stands back and lets him back into Downing Street.
"If Ed Miliband and Labour do that, they will not be forgiven, certainly in Scotland and I suspect in large parts of the UK as well."
"It was very clear last night that on its own, Labour is not going to be bold enough to offer a real alternative to the Tories," she added.
Nicola Sturgeon had a stark warning for Ed Miliband in the challengers' debate.
The SNP leader said: "For me it's about... real change for people right across this country, don't turn your back on that Ed and let David Cameron back into Downing Street."
Watch the full exchange between the two leaders:
Ed Miliband said he is not like David Cameron when compared to the Prime Minister.
However SNP leader Nicola Sturgeon claimed "there is not enough difference" between the two leaders. Her comments were met with applause suring the live TV debate.
First Minister Nicola Sturgeon has called on Labour voters to back the SNP instead in the General Election in May.Read the full story ›
Nicola Sturgeon has denied Ed Miliband's "desperate" claim that there are billions of pounds of cuts on the horizon under the SNP's plan for full fiscal autonomy for Scotland.
The SNP leader claimed that Labour is "wrong" while campaigning on the streets of Stirling, saying:
This is desperation on the part of the Labour Party. Instead of putting forward a positive case of their own, they are resorting to the same fears and smears that they resorted to during the referendum.
The truth is the only cuts on the horizon for Scotland are the ones that the Tories are proposing and Labour are backing.
Nicola Sturgeon has hit back at Scottish Secretary Alistair Carmichael over the leaked memo row, saying he should "question his whole approach to politics" if he thinks dirty tricks are a normal part of election campaigns.
"I take a very different view. I think elections should be a battle of positive ideas and that's how I'll continue to campaign," the SNP leader said.
Cabinet Secretary Sir Jeremy Heywood has ordered an inquiry into how the note - which claims Sturgeon told French ambassador Sylvie Bermann that she would prefer to see Conservatives remain in power after the election - got into the public domain.
Sturgeon insists the allegation has been "completely answered" and has called for the investigation to provide answers as soon as possible.
Cabinet Secretary Sir Jeremy Heywood has ordered an inquiry into an alleged leaked PM 'preference' memo.
It follows reports that a civil service account of Nicola Sturgeon's private meeting with the French ambassador was obtained by The Telegraph newspaper.
UKIP leader Nigel Farage reacted to the allegations that the SNP's Nicola Sturgeon expressed a preference to see David Cameron as prime minister after the general election over Ed Miliband, by claiming the "SNP want to break up Britain".
Speaking on the campaign trail Farage said: "The SNP want to break up Britain. The way they see it, if the Tories are strong - given the level of toxification of the Tory brand in Scotland - that will help them. I guess that's what it's about."
A Labour spokesperson has said today that the SNP and the Tories are "locked in an unholy alliance" and the public should not believe stories about a Labour-SNP coalition.
“The Tories know that the SNP are David Cameron’s last hope of clinging on to power – and the Tories care a lot more about that than they do about the future of the United Kingdom.
“And we know the SNP care more about a second referendum than they do about stopping Tory austerity.
“So forget all the silly scare stories about a Labour-SNP coalition. The truth is that the SNP and the Tories are locked in an unholy alliance.”
David Cameron has told Conservative supporters today that SNP Leader Nicola Sturgeon's alleged comments that Mr Miliband was not "prime minister material" was nothing new.
Speaking in the Oxford West and Abingdon constituency the Prime Minister said he had made the same comments four years ago: