GORDON Brown has claimed to have "nailed the Nationalist lie" on NHS spending as the No camp said secret documents showed the SNP Government was to make up to £450 million of health care cuts but was only going to tell Scottish voters about them after tomorrow's referendum vote.

The Scottish Conservatives also suggested the SNP Government had delayed the announcement of its annual budget from September to November to "keep their cuts secret" until after the referendum.

But Alex Salmond hit back swiftly, saying Better Together campaign's allegations were "absolutely untrue" and the figures being quoted referred not to cuts but to efficiency savings that would be ploughed back into Scotland's health service.

The war of words came as Mr Brown used his final campaign speech to launch a blistering attack on the Scottish Government's argument that it was being penalised on health spending by the UK Government and could only control expenditure with independence.

In a passionate speech at Clydebank Town Hall, the former Prime Minister held up a copy of the Scotland Act to emphasise how the Scottish Government had the power to keep the NHS in public hands and declared: "The NHS lie of the SNP has been exposed."

To applause, he told an audience of No supporters: "If the SNP continue to say they are powerless to protect the NHS in Scotland, let them make way for a Labour government in Scotland and we will protect the NHS."

Mr Brown added: "The biggest threat to the NHS in Scotland is actually the SNP; the biggest threat is they will not pass on the money they have from Westminster that is allocated to the health service and will give it less.

"The biggest threat is they are going to allow £450m in cuts to take place that they haven't announced before the referendum but will announce in the days after the referendum."

Alistair Darling, the Better Together campaign leader, who also spoke at the Clydebank event, accused the SNP leadership of trying to deceive the public and said they were guilty of "quite appalling" behaviour.

According to leaked papers presented last month to health board chief executives and civil servants, new NHS obligations were "not fully funded" and the "status quo in terms of service and workforce planning is not an option". Suggested options included centralising hospitals and closing services.

However, Mr Salmond dismissed the claims of cuts as "mythical" and pointed to plans passed at Holyrood earlier this year showing the overall budget was due to increase from £11.9bn to £12.7bn next year.

"What this paper does is part of the normal planning in the health service. It says we'll need 3.5 per cent efficiencies to meet commitments in the rising cost of procedures in the health service. In the last six years, we have managed 3 per cent and that's all been ploughed back, every single penny of it, into the health service. That's why we have increased funding in real terms."

Nicola Sturgeon, his deputy, described the papers as a "discussion document" written in the context of the status quo, not in the context of independence.

She suggested the No campaign did not realise it was making the Yes case "because the centre of the case around the NHS is that yes, we've got policy control, but we don't have control over our own resources, and as long as we remain at the mercy of Westminster cuts to our overall budget, then it gets harder to protect the things that matter."

Alex Neil, the Scottish Health Secretary, branded Mr Brown's comments a "spectacular own goal", saying: "We've fully protected Scotland's NHS within our fixed budget despite the Tories' cuts to Scotland. With a Yes vote and independence we can make sure it is never again under threat from Tory-led ­Westminster austerity."

Last week, the Institute for Fiscal Studies contrasted the planned NHS cuts of 1.2 per cent in Scotland in 2015/16 with an increase of 4.4 per cent in England.