Labour leader Johann Lamont was branded a "poster girl for the Tories" as she mounted a defence of a major policy shift by her party.
Ms Lamont had earlier this week called for an end to the "something for nothing" culture as she announced Labour was setting up a special group to look at the economy.
She warned taxes would have to rise or services will be cut to maintain popular but expensive SNP pledges on areas such as the council-tax freeze, the provision of free university education and free prescriptions.
But Deputy First Minister Nicola Sturgeon hit out at the party's change of stance, demanding: "Whatever happened to Labour?" and challenging Ms Lamont to make it clear if she wanted to scrap policies such as free prescriptions and the council-tax freeze.
She hit out at Ms Lamont in a heated exchange at Holyrood, where the Labour leader questioned whether it was fair that someone earning as much as the Deputy First Minister should, for example, receive prescriptions free of charge.
Ms Lamont said: "Like me, she will have saved more than £400 from the council-tax freeze, yet my children's school and schools across the country are getting to the stage where they can't even do the basics like photocopying materials.
"If spending cuts threaten the kind of free care for the elderly we want to deliver, is it fair a woman like her on £200,000 gets free prescriptions?" and insisted there needed to be a debate about "which cuts you make in tough times".
In a speech this week, Ms Lamont had highlighted the rapidly-expanding number of older people and the squeeze on the country's finances.
The pair clashed when Ms Sturgeon stood in for Alex Salmond at First Minister Questions in the Scottish Parliament, as the SNP leader is in the US on business.
The exchanges began with the Deputy First Minister stressing the Scottish Government's commitment to policies such as the council-tax freeze.