Scottish independence: Free healthcare 'guaranteed' in constitution
Alex Salmond has proposed the inclusion of a right to free healthcare in the written constitution of an independent Scotland.
The first minister said the NHS in England was facing a programme of steady privatisation, but Scotland had a chance to choose a different path.
Supporters of the Union have accused Mr Salmond of scaremongering.
They have pointed out that health policy is devolved, with decisions about the NHS already made at Holyrood.
The founding principle of the NHS - set up in 1948 under UK Health Minister Aneuryn Bevan - was healthcare free at the point of delivery and based upon clinical need, not the ability to pay.
Mr Salmond said: "For me that is not a simple a matter of policy, it's a fundamental part of Scotland's national identity.
"In England, despite the protest of many, the NHS is being eroded and the founding principles handed down by Bevan have been scorned and betrayed by successive Westminster governments.
"It's now well understood that voting 'Yes' will allow us to protect Scotland's NHS from the threat to budgets here as a consequence of the cult of austerity and privatisation being forced on the NHS in England."
The guarantee of free healthcare would be proposed for consideration by a constitutional convention, which would be given the task of drafting a written constitution for Scotland if voters back independence in the forthcoming referendum.
The first minister has previously claimed that an agenda of "privatisation and fragmentation" at Westminster could impact on Scotland through the Barnett formula, which allocates spending across the UK.
But opponents have dismissed his claims and said they were designed to scare voters.
Pro-UK campaigners have previously argued that remaining part of the UK would "secure the best future" for the NHS in Scotland.
Labour MSP Jackie Baillie said: "By pooling our resources across the UK, Scotland's NHS gets almost 10% more spending per head of population than in England.
"That means that yearly health spending is around £200 per person higher than the UK average.
"This is a clear positive benefit of staying in the UK."