Vince Cable will insist the Liberal Democrats are the party to lead Britain out of recession - having warned of the financial dangers in the first place.
The Lib Dem Treasury spokesman will claim his party led the debate as the economy went down and is also right about what the Government needs to do next.
In his keynote speech to the Lib Dem spring conference in Birmingham, Mr Cable will tell voters his party will be both fair and fiscally responsible.
"We, the Liberal Democrats, were right about the financial crisis," he will say. "We warned of the dangers and we led the debate when the crisis came. And now we have a clear vision for the future of the British economy.
"What the public wants to know is who can guide the country out of the present morass: the broken, discredited, banking system; the deepest and longest post war recession, whose effects are far from over; and levels of government borrowing which are not sustainable. We can."
Lib Dem leader Nick Clegg went into the weekend gathering insisting that the general election was still "wide open".
At a rally on the eve of Saturday's first formal sessions, he exhorted activists to "go for broke" and voters to choose "something different".
He will be joined in Birmingham by former Tory MEP Edward McMillan-Scott, who was on Sunday unveiled as the Lib Dems' latest recruit.
Mr McMillan-Scott, once leader of the Conservative MEP faction in the European Parliament, rebelled against David Cameron's decision to break away from the centre-right European People's Party in Europe.
He was expelled by the Tories six months ago, since when he has been sitting as an independent.
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