The First Minister spoke out after being accused of spreading "the biggest lie so far in the referendum campaign" by claiming Scotland's NHS was at risk as a result of privatisation within the health service in England.
His comments came as a TNS survey showed support for Scotland remaining in the UK had risen sharply over the past month as undecided voters backed a No vote.
A separate poll showed six out of 10 GPs and hospital doctors intended to vote No, in a blow to the Yes campaign's growing efforts to make the future of the NHS a key referendum issue.
But last night Mr Salmond raised the stakes, insisting the principles laid down by Nye Bevan, health minister in the post-war Labour government and architect of the NHS, should be enshrined in the constitution of an independent Scotland.
He said: "Nye Bevan's founding principles for the National Health Service were for an institution owned by the people, which ensured that all have access to the highest attainable standard of health services, free at the point of delivery, based on clinical need and not ability to pay.
"For me that is not a simple a matter of policy, it's a fundamental part of Scotland's national identity."
He claimed the privatisation of services south of the Border "scorned and betrayed" the founding principle of the NHS. In England, a number of new contracts to provide NHS services have gone to private companies, leading to accusations that reforms of the system have led to creeping privatisation.
Mr Salmond repeated controversial claims that contracting out services to private providers in England would threaten the Scottish health service's budget, insisting the risk was "well understood". He added: "But protecting the budget of our health service is only the first step. With independence we have the golden opportunity to enshrine Bevan's founding principles for our National Health Service in the written constitution for Scotland - publicly owned, clinically driven, and freely delivered equally for all.
"Constitutional protection for the NHS is our promise to generations yet to come that in the Scotland we seek, no-one will be denied medical aid because of lack of means. The NHS is at the heart of our nation, and I want it to be at the heart of our constitution."
The commitment was not included in the Scottish Government's draft constitution, published in June.
Since then, Mr Salmond and other leading Yes campaigners have become increasingly vociferous in claiming that Scotland's NHS, which is the responsibility of Holyrood, is threatened by privatisation in England.
In a letter published in The Herald yesterday, Labour's health spokesman Neil Findlay described the claim as "the biggest lie so far in the referendum campaign". He said that while he opposed privatisation it had not led to budget cuts in England and, as a result, Scotland did not face knock-on cuts under the Barnett Formula public funding mechanism.
Meanwhile, the survey by the British Medical Journal found 60 per cent of Scots doctors questioned intended to vote No in the referendum.
One-third said they would back Yes while seven per cent were either undecided or planned not to vote. The findings were based on responses from 311 medics, mostly GPs and hospital doctors.
Commenting on the findings, Lothian MSP Mr Findlay said: "This survey blows the SNP's attempts at scaremongering on the future of the NHS out of the water."
He said the SNP had increased spending on private healthcare by 23 per cent, and accused the party of "resorting to desperate tactics in a campaign that is losing credibility at an alarming rate".