Ed Miliband has ruled out a confidence and supply deal with the SNP after the general election.
Asked if he would negotiate with SNP leader Nicola Sturgeon in the event of a hung parliament, Mr Miliband told the BBC's Andrew Marr: "It's not happening".
The Labour leader added: "I want to be clear about this. No coalition, no tie-ins. I'm not doing deals with the Scottish National Party."
Mr Miliband had already ruled out a formal coalition but had so far declined to comment on a potential looser arrangement with the Scottish nationalists - which had been seized on by the Conservatives.
He accused the SNP and the Conservatives of wanting to "set England and Scotland up against each other", promising his party will represent the whole of the UK.