Scotland's former Auditor General Robert Black has questioned whether providing the current range of free public services can remain sustainable.
Decisions to offer free personal and nursing care and concessionary travel fares should be revisited, he said.
Mr Black said the cost of such services in Scotland had risen more than anyone had expected when they were introduced.
He went on to say there was an urgent need for reform, including fewer councils and other public bodies.
The Scottish government said it remained commited to the council tax freeze, free prescriptions, free bus travel and its public service reforms.
Scottish Labour leader Johann Lamont signalled a major policy shift for her party last week by criticising the "something for nothing" society, and casting doubt on Labour's support for free university tuition, the council tax freeze and free NHS prescriptions.
Speaking to the BBC's Newsnight Scotland programme, Mr Black said: "The move being made by the Labour party in Scotland to at least start asking questions is a good thing.
"We need to do more of that but we need to do it as a society. I mean can we really afford all the services that are free at the point of delivery?
"If you take free personal nursing care and the national concessionary travel scheme, the free bus passes. When those schemes were set up there was no hint given that the costs of those would be rising as quickly as they are now.
"As we said in Audit Scotland reports in my day, the concessionary travel scheme could cost not far short of half a billion pounds by the time we get through to the 2020s.
"Were the MSPs aware of that when they launched the policy? I suspect the frank answer is not. So to that extent I think I am on safe ground by saying the affordability of some this has to be questioned, we do need to revisit it. Every pound that goes on bus passes for well off older people is a pound that is not available for other things."
In a wide-ranging lecture in Edinburgh on Thursday, Mr Black also listed rising costs and backlogged maintenance that are forcing a re-think of spending priorities.
He claimed MSPs have become too cut off from the way services are delivered in local communities. He argued they should spend less time on passing unnecessary laws, to free up more time for budget scrutiny.
The former watchdog and council chief executive said the scrutiny would be helped by a new commission to investigate whether public services are being well and efficiently run.
Mr Black was the first to hold the post of Auditor General, and led Audit Scotland for 12 years.
The lecture at the David Hume Institute was his first detailed reflection on his time in office.
He warned politicians have only had "coping responses" to challenges in public services, but urgently need to work on longer-term ones.
Talking about the independence referendum, he said: "Whether the outcome is more devolution or complete independence, we will be facing the same challenges in our public services as we do today.
"The political and media focus on the independence issue is leaving little space or opportunity to address the great challenges which we are facing.
"Time is not on our side. The challenges are immediate and require an urgent response. We cannot afford to place this agenda to one side until after 2014."
He went on: "There is clear leadership on the independence debate, but on many of the other big issues, it can feel as if the politics of Scotland hasn't fully come to terms with the challenges we are now facing.
"No one party or leader is prepared to take the risk of being the first mover in re-thinking policies, whether it be penal reform (or) reshaping the health service".
Mr Black cited the growth in police numbers from 6,900 in 1949 to more than 17,000 now, despite the use of technology for policing, and without any politician asking why the higher numbers are necessary.
He said scrutiny of public services is "episodic and patchy" and "mostly conducted at Holyrood, remote from the localities where the services are delivered".
And while he said there has been extensive attention paid to budget cuts, less has been paid to rising costs, including:
- A £4bn backlog in roads and public building maintenance.
- The cost of travel concessions rising to £500m in the next decade.
- Council costs of waste management rising to £580m
- Personal and nursing costs rising by 15% each year.
- Free prescription and eye tests costing £150m each year.
- Drug prescribing costs double what they were a decade ago.
- The estimated cost of health and social care for people over 65 rising to £3.6bn by 2030.
The speech featured strong criticism of the lack of data with which to tell what is being spent on public services and how effectively. Mr Black said he was disappointed at the "glacially slow" progress despite repeated calls from Audit Scotland.
And he said that partnership working between councils, health boards and other bodies has become too complex and ineffective, without adequate financial controls.
He warned that councils lack a knowledge of the way other organisations provide social care, and are already threatening their survival by cutting funds.
He suggested a national body should be set up to help councils contract for social care, providing expertise that is not available to many of the 32 councils.
And he reported that, in discussions with leading figures across the public sector, he had found strongly-held feelings that they were not getting support from political leaders "in openly addressing the real challenges of choosing priorities and driving down costs while maintaining service access and quality".
In response, Finance Secretary John Swinney said: "Our support for key universal benefits such as personal care for the elderly and prescriptions reduces costs in our hospitals, whilst the bus pass ensures our elderly can access services, remain part of their communities and benefit from the full range of public services available to them.
"All of these services and the others that we fund, such as free university education, are by definition affordable because they are being paid for now from within a fixed budget.
"Through the integration of our public services, including reform of police and fire services and delivery of adult social care, implementation of a public sector pay freeze, the delivery of a substantial efficiency programme, the reduction in the number of public bodies and a decisive shift towards early intervention, our actions ensure that we can protect essential services now.
"It is clear that whilst we can continue to manage declining UK spending, an independent Scotland will provide the economic levers to further stimulate growth, enhance productivity and strengthen the sustainability of our public finances."
Mr Black's comments were welcomed by Ms Lamont, who said: "The truth is that whatever government is in power, and whatever our constitutional arrangement, Scotland faces a public spending crisis. Every western country is facing these problems although ours are made worse by a Tory government which is cutting too far and too fast.
"This isn't about universal benefits versus means testing, it is about affordability. It is about examining policies which were affordable in times of growth, but which have become slogans which hurt those in need in times of recession".