Labour has accused the Conservative Party of "bigging up" Scottish National Party leader Nicola Sturgeon in a bid to prevent Ed Miliband winning the 7 May 2015 general election.
Sturgeon was seen as one of the winners of the 2 April 2015 party leaders' TV debate. She was praised by senior Tories, such as former Chief Whip Michael Gove, who told BBC Radio 4's Today programme on 3 April: "I think it's probably fair to say that the three female leaders all did very well, in different ways. I think it's also legitimate to say that Nicola Sturgeon emerged as the most impressive debutante on the stage, she did very well."
Sturgeon, whose party looks likely to win a landslide in Scotland, said that if the election delivered a landslide for the SNP and Labour made a deal with the nationalists then together they actually lock the Tories out of Number 10.
But speaking shortly after the Labour campaign bus arrived in Blackpool, north west England, Ed Miliband said his position on ruling out a formal coalition with the SNP had not changed as a result of Ms Sturgeon's success in the debate.
And Labour's Caroline Flint said: "There is not going to be a coalition with the SNP and there are not going to be any SNP ministers, I can assure you that and [former SNP leader] Alex Salmond certainly will not be Deputy Prime Minister.
"I think there is something pretty shallow about the processing discussions about coalitions and deals. You know we hear[Chancellor of the Exchequer] George Osborne and Michael Gove bigging up the SNP because they know that every vote for the SNP is more likely to secure David Cameron the keys to number 10 for another five years."
And the Scottish First Minister denied Labour claims that she was handing the Tories a victory.
She said: "If Labour and the SNP combined to have more seats than the Tories we can lock the Tories out of government. But crucially if SNP is a big force in Westminster we can make sure a Labour government does not sell out on its values like the last Labour government did."
Cameron warns against another coalition
Meanwhile, Prime Minister David Cameron warned against a post-election coalition government.
Speaking in Manchester, where he was meeting people who had benefited from the Government's Help To Buy scheme, Cameron said: "My impression of the debate is very much that there is one person, one leader, one party that is offering the competence of a long-term plan that is working and then there is a kind of coalition of chaos out there that wants more debt, spending and taxes."
His comments echoed those made by Gove earlier in the day. He said: "If the country chooses to, it could vote for a patchwork coalition… I prefer to say a lethal cocktail of different parties which all have different objectives – there would be an automatic instability."
However, LibDem leader Nick Clegg said the debate had made it increasingly clear that another coalition would be the outcome of the vote in May.
He said: "The fact that there were seven there just shows that politics is becoming more fragmented. The only people who don't realise that are Ed Miliband and David Cameron – they think it's still a game of pass-the-parcel between the two old parties."