Nicola Sturgeon has set out a list of demands she would make in return for backing a minority Labour government to keep Boris Johnson out of Number 10.
Ms Sturgeon made clear that Labour would need to back the “principle” of a second independence referendum.
The first minister said she would also seek greater powers for the Scottish Parliament and an end to austerity.
But the SNP leader insisted she would not form a formal coalition with Labour if there is a hung parliament.
Instead, she said her party would potentially be willing to back a minority Labour government led by Jeremy Corbyn on an issue-by-issue basis.
The SNP won 35 seats in the last general election in 2017, making it the third largest party in the House of Commons.
But Ms Sturgeon again warned that other parties “need not bother picking up the phone” to her after the election unless they are willing to support her party’s right to hold an independence referendum next year.
She said her party would drive a “hard bargain” with anyone seeking SNP support in the event of a hung parliament – and explicitly ruled out doing any deal with the Conservatives.
Ms Sturgeon’s list of demands for SNP support included the “principle of the people of Scotland deciding our own future”, as well as the devolution of powers over immigration, employment and drug laws.
Prime Minister Boris Johnson said during a visit to Scotland on Thursday that he would fight to “keep our fantastic United Kingdom together and prevent another referendum next year”.
The Liberal Democrats are also firmly opposed to another independence referendum – while Labour leader Jeremy Corbyn has said indyref2 is neither “desirable or necessary” and has indicated he would not support one in the “formative years” of a Labour government.