The SNP has been accused of failing to set out how it will continue to pay for universal services.
The party was challenged to explain by the end of 2012 how policies such as free NHS prescriptions can be funded over the next decade.
Conservative finance spokesman Gavin Brown called for Finance Secretary John Swinney to publish the details during a Holyrood debate on public service provision on October 3.
The issue shot up the political agenda when Labour leader Johann Lamont used a speech one week earlier to criticise a “something for nothing” society, casting into doubt her party’s support for free university tuition fees, the council tax freeze and free prescriptions.
She has since gone further by suggesting in a speech last month that students should pay towards their education.
Mr Brown said the finance secretary should be able to set out a 10-year plan so the issues can be discussed properly.
“It should have been straightforward for John Swinney to present a 10-year plan, especially with him having most of the information to hand,” he said.
“Asking the SNP to provide such details by the end of the year was not an unreasonable request.
“But needless to say it has failed to do so we always set the Scottish Government low expectations, and yet again it has delivered in full.
“Of course we need a debate on the future of universal free services, but I don’t think we can have that debate until we have the necessary data.”
A Scottish Government spokesman said: “The Scottish Government has delivered a balanced budget in every single year and still protected the council tax freeze, free university education, free prescriptions and bus passes for our oldest citizens.
“The UK Treasury has not published figures for what Scotland will receive under the current constitutional settlement for the next decade and it is simply not possible for the Scottish Government to publish a budget over this time period without these figures.”