The SNP will "work like never before" to turn the party's current popularity in the opinion polls into MPs at Westminster, the party's deputy leader will pledge.
Stewart Hosie will say that at the moment the high poll ratings that nationalists are enjoying is "only potential".
With less than six weeks to go to the general election, he will say that a vote for the SNP is needed to help bring about an end to austerity and deliver more powers for Holyrood.
Mr Hosie, who suc ceeded Nicola Sturgeon as SNP depute last November, will close his party's conference in Glasgow this afternoon.
He will stress to delegates: "T he only way to make sure Westminster delivers - on anything - will be to return the largest ever number of SNP MPs to Westminster."
With both the Conservatives and Labour " signed up to another £30 billion of cuts" he will say the UK is "on track for a decade of austerity - unless we achieve change by voting SNP for investment in jobs and growth".
Mr Hosie, the MP for Dundee East, will insist that while "a usterity has failed" the nationalists offer a "real alternative" to this in May's election.
" A vote for the SNP is a vote to say 'enough is enough' to Tory, Labour or Lib Dem austerity cuts," he will declare.
"A vote for the SNP will give the people of Scotland the power to achieve real change in Westminster."
Mr Hosie will add: " We know the opinion polls are in our favour. But this is only potential.
"Our job is now to work like never before. To turn this electoral potential into votes and seats. If we do that then this nation will prosper and flourish."