The Labour leader declared he could not “do a deal with a party that wants to break up the UK when we want to build it up”.
But SNP leader Nicola Sturgeon claimed his refusal to work with her to keep out a Tory government would be the final nail in Labour’s coffin in Scotland.
At an election rally in Glasgow Mr Miliband said: “I know the people of Scotland want a more just society. And with food banks, payday lenders and the neglect of the NHS, Scottish people feel there must be no delay.
“That’s why I have a clear message for the people of Scotland today: don’t gamble with the SNP when you can guarantee change with Labour.”
Mr Miliband said in a special TV Question Time on Thursday night that he would rather forego power than rely on a deal with the SNP. That prompted Nationalist claims he would prefer to see the Tories in government.
But Mr Miliband said the SNP taking seats from Labour would increase Tory chances of being the largest party. And he vowed: “I will never put the Tories into government. I have spent my entire political career fighting them.
“But the tragedy is that the SNP may very well let the Tories in. That’s what could happen if the Tories are the largest party.”
Ms Sturgeon, who went campaigning in Musselburgh yesterday, said Mr Miliband’s stance would drive more voters to the SNP. She said: “If Ed Miliband is really saying he would rather have a Tory government than work with the SNP for more progressive politics, then it’s final proof that Labour has lost the plot.
“It will be the final nail in the coffin of Scottish Labour, and I suspect Labour in other parts of the UK, and it makes it all the more important that we have a big team of SNP MPs because we will need them to protect Scotland from the Tories because clearly Ed Miliband is not prepared to do it.
“I think Ed Miliband is saying these things because he’s being bullied and bossed around by the Tories on this.”