Nicola Sturgeon has repeated her scepticism that a formal Labour-SNP coalition is on the cards.
But she voiced the hope that a “progressive alliance” could be formed that will make Westminster “work for ordinary people, not just for politicians”.
The first minister made her comments as she outlined policies to tackle child poverty, including increasing child tax credits and child benefit, using money from scrapping Trident to expand childcare, and boosting the minimum waged to £8.70.
Ms Sturgeon said Labour leader Ed Miliband’s failure to give a commitment to keeping the Conservative’s out of power, even if they are the largest party, gives the impression he would prefer to see David Cameron in Downing Street than work with the SNP.
“If that is the case, then people in Scotland, I don’t think, will ever forgive the Labour party,” she said.
The first minister added: “I repeat that call to Ed Miliband today, and maybe today unlike the previous few days he will answer that.
“If we have an anti-Tory majority, will he work with the SNP rather than allow David Cameron back into Downing Street?”
Ms Sturgeon said years of austerity had harmed the poorest 10% of households harder than anyone else, unfairly making children pay the price.
Current UK plans will see 1million additional children across the UK grow up in poverty, 100,000 of them in Scotland, she said.
“Labour remain committed to austerity and to welfare cuts – but I know there are many in the Labour party who, like us, want to see an end to austerity. It is only SNP pressure that will make it happen,” Ms Sturgeon said.
“If we have influence and the opportunity to form a progressive alliance then we can drive change at Westminster and we can make Westminster work for ordinary people, not just for politicians.”
Scottish Liberal Democrat president Sir Malcolm Bruce called on the SNP to come clean on whether it planned to reverse welfare changes since 2010, a message it has spent five years shouting.
“If so, where are they going to find the money that they have said would be £2.5billion for Scotland alone?” he said.
“If they are not, people will expect them to admit that they are not going back to 2010. SNP voters will believe they’ve been led up the garden path