The SNP’s leader promised her party would reform the “discredited” Westminster system for ordinary people, wherever they lived in the UK.
Nicola Sturgeon told a gathering of party faithful in Glasgow that a shake-up was needed to bring positive change.
She also said it was time to abolish the House of Lords where members are paid “£300 a day for just showing up”.
Voters throughout the UK go to the polls on 7 May to decide who will be their next MP.
The latest polls indicate the SNP is on course to winning most of Scotland’s 59 Westminster seats and the Labour and Conservatives would fail to win an overall majority in the House of Commons.
This has led to suggestions the nationalist could play a power broker’s role in the event of a hung parliament.
Ms Sturgeon said: “I think I can safely say that we do still want Scotland to be independent.
“But at this General Election – with the power of the big parties weaker than ever before – I say this to people of progressive opinion all across the UK.
“As long as Scotland remains part of the Westminster system, we will be your allies in seeking to shake up and reform that outdated and discredited system once and for all.
“Westminster needs to change. To be more responsive to the needs and demands of ordinary people, wherever they are in the UK.
“So to people in England, Wales and Northern Ireland, I make this promise. The SNP stands ready to work with you in making that positive change for all of us.”