Alex Salmond is not being honest with the Scottish people about the consequences of independence, Labour's leader north of the border said today.
Johann Lamont claimed the Scottish National Party was avoiding the "tough questions" on independence, telling delegates at the Labour Party conference in Manchester there was a need for an "honest debate" about breaking away from the United Kingdom.
She also hit back at claims by the SNP that she was a poster girl for the Conservatives, after she questioned whether Mr Salmond's spending plans were affordable.
Ms Lamont said: "The SNP might not have the courage to be straight with the Scottish people but we do.
"What Alex Salmond is doing with Scotland's finances is the equivalent of putting the gas bill in the drawer.
"We've all done it - not opened the bill because we feared the consequences. So we stuff it away. And the reminder. And the final notice. But we all know that never ends well.
"Salmond hopes we won't ask the tough questions about independence and he is desperate we don't ask the tough questions of the here and now.
"He knows that every Scottish family is bearing the cost of his slogans. We all know that his budget will go bust.
"But he hopes that somehow he can keep the truth from the Scottish people until after the referendum.
"I won't wait until after the referendum to be honest with the people of Scotland. We need an honest debate now about how we protect the most vulnerable from the cuts. Not everyone is going to like the solutions - that is unavoidable.
"But I will be straight with people now about what is to come, and I will be true to Labour values - that we will not allow those who most need our support to pay the price for populist slogans."
The Scottish Labour leader has rejected claims that she is a Tory for questioning universal benefits such as free NHS prescriptions.
Last week, Ms Lamont faced sustained criticism from her Holyrood opponents for casting into doubt popular but expensive Scottish Government policies which also include free university tuition and a council tax freeze. The SNP branded her the poster girl for the Conservatives after she called for an end to a "something-for-nothing" culture, arguing that taxes will have to rise or services will be cut.
Yesterday she hinted that taxes could go up once Holyrood gets new financial responsibilities through the Scotland Act in 2016, assuming a No vote is returned in the 2014 independence referendum and Labour is returned to power.
The Act, which became law earlier this year, provides for the income tax rate in Scotland to be reduced by 10%, with the Scottish Parliament then responsible to bring it back up or make variations.
But Ms Lamont, making the first speech to the UK party conference as an overall leader for Scottish Labour, vehemently denied the charge she was a Conservative stooge.
She said: "The people of Scotland know that nothing is free. And every day we see more clearly that the costs of Salmond's slogans are being borne by hard-working families struggling to make ends meet, borne by the elderly and vulnerable seeing their care slashed, borne by the student who can't get a place in further education.
"Now last week, when I pointed out that Scotland's families are paying for Salmond's unsustainable tax break for the rich, I was accused of being a Tory.
"I'm not sure if the cap fits with someone who campaigned against Thatcher's cuts to Scotland in the Eighties.
"Not sure the cap fits with someone who campaigned for a Scottish Parliament to protect Scotland from future Tory governments.
"And I am not sure the cap fits with someone who sees in surgeries, in meetings and in everyday life the consequences of a Tory Government cutting too far and too fast while we have an SNP Government content to amplify the cuts rather than protect people from them."
But SNP MSP Mark McDonald said: "The problem for Johann Lamont is that the Tory cap fits her very well."
She has been "praised to the skies by the Tories in Scotland and even by Tories in Wales", he said.
"It may be excruciatingly embarrassing for Johann Lamont but her speech was immediately welcomed by the Welsh Tories who tweeted 'Well said Johann Lamont'.
"In threatening to cut public services invested in by the SNP Government such as free personal care, reintroduce prescription charges on the sick and impose tuition fees, Ms Lamont has become the Tories' poster girl in Scotland, Wales and no doubt England too."