Ed Miliband's attempt to "weaponise the NHS" certainly worked.

Unfortunately, the weapon has been grabbed out of his hands and fired in his face, and not just by David Cameron at Prime Minister's Question's yesterday. Unreconstructed Blairite "modernisers" like former Health Secretary Alan Milburn and former Labour Business Secretary Lord Hutton have been eagerly handing ammunition to the Tories as Labour's message on the NHS becomes ever more confused.

Milburn and co have said, effectively: hold on a minute, you can't suddenly dismiss Labour's contribution to the market-based reforms of the NHS as if it never happened. Labour were the ones who pushed ahead with what is now being called "privatisation": opening up NHS service contracts to private competition. What Andy Burnham now calls the "Tory market experiment in the NHS" was actually Labour's experiment.

And painful it was too. Remember the "scars on my back" that Tony Blair complained about after trying to break down what he called the old "top down" monolithic NHS? He made market reforms the keynote of his second and third administrations. The "any willing provider" principle that required English Primary Care Trusts to accept tenders from private firms, and not just the NHS, was introduced by Labour.

Indeed, it was Andy Burnham who gave the go-ahead for the first fully privately run NHS hospital, Hinchingbrooke in Cambridgeshire, which collapsed last year after it was criticised by the Care Commission. In Scotland, Labour's First Minister Jack McConnell experimented with privatisation at Strathcathro hospital in Brechin in 2006. This first and last private sector treatment centre was fully integrated back into the Scottish NHS in 2010.

Ed Miliband is not going to be allowed to forget all of this. Blairite modernisers including one Jim Murphy believed passionately that it was their "patient centred" market reforms that helped Labour to win three straight elections. Alan Milburn twisted the knife by comparing Ed Miliband to Neil Kinnock in the 1992 General Election, which was a little unfair on Neil Kinnock. He at least managed to restore Labour's electoral credibility in 1992 and, though he didn't win, Mr Kinnock arguably laid the ground for the victory five years later.

In 1992 Labour sort of knew what it stood for. Today, it is a mass of contradictions. It is futile for Ed Miliband to pretend that somehow Tony Blair was a momentary aberration; that he was on holiday when it all happened. Tony Blair was Prime Minister for three consecutive terms and Ed Miliband was one of his key policy advisers, working mostly for the Chancellor, Gordon Brown, who oversaw the market reforms.

But history has to be rewritten because Labour has discovered, much as Alex Salmond did towards the end of the referendum campaign, that the NHS is a touchstone issue and voters are intensely concerned about any risk of privatisation. Andy Burnham has been barnstorming round the country saying the NHS cannot survive another five years in much the same way that the Yes Campaign did after Dr Philippa Whitford's claims about privatisation went viral in June last year.

Better Together cried foul against the Yes Campaign, claiming that the Scottish service was under no direct privatisation threat from England. And they had a point. Nicola Sturgeon, amid great fanfare, had announced in 2008 that she had "outlawed" private sector competition from the NHS, though the service still uses private health to cover shortfalls in care. She now says that English privatisation threatens the funding of the NHS in Scotland through the Barnett Formula consequentials, though there has been little sign of this so far.

However, the problem for Labour is that, when the SNP were outlawing private competition for NHS contracts, they were actively promoting it. It started with the public/private independent surgical treatment centres in 2005 to speed up elective surgery. Under Labour, NHS foundation hospitals became free-standing non-profit making companies that could borrow on the private money markets and provide private care subject to limits.

According to the independent health care charity, the King's Fund, Labour significantly extended the internal market reforms introduced by the Conservatives in the 1990s. "These changes went further [than the Tories] towards creating a market" said the fund in its 2011 review of Labour's health policy.

In the 2012 Health and Social Care Act, the Coalition vastly extended this private provision by effectively pitching most NHS service providers into open competition with the likes of Virgin Health, Serco and Circle. In the first year of the Act more than half of NHS health contracts went to private providers.

Many NHS hospitals were plunged into the red. A succession of scandals, such as at Mid Staffs Foundation Hospital (not directly related to privatisation) has heightened public alarm and the NHS is racing up the list of key issues in the General Election campaign. Labour saw an opportunity to attack the Tories on an area where they have traditionally been vulnerable. Voters have never trusted the Tories with the NHS and are highly receptive to messages that it is being privatised.

Of course, the Conservatives deny this and say that health is still free at the point of need, the fundamental principle on which the NHS was founded. All that's happened is that the private sector has been brought in to boost efficiency through competition and increase patient choice. These, they say, are the same motivations behind Labour's version of the internal market when they were in office.

However, it is hard to look at the service in England that is emerging today and not agree that it is being radically altered by the wholesale invasion of private provision. Andy Burnham has promised to repeal the Health and Social Care Act if Labour are returned to government and the Scottish National Party has promised to help him. Nicola Sturgeon says she will make it a part of any coalition deal; an offer that Labour's Shadow Chancellor, Ed Balls, apparently has no difficulty refusing.

Many believed that the Scottish Government's legislation against private provision on the English model was an ideological step too far. However, with the liberalisation measures proposed in the forthcoming Transatlantic Trade and Investment Partnership (TTIP), this move makes more sense. It is generally accepted that only a uniform publicly provided health service is exempt from legal challenge under TTIP rules. Andy Burnham has added exclusion from TTIP to his list of reforms needed to keep health public.

But the problem is that Labour's approach to the NHS is confused, contradictory and many would say grossly hypocritical. As Andy Burnham demonstrated in a disastrous Newsnight interview this week, it is almost impossible to articulate Labour's policy on private provision. When it was pointed out that most of the privatisation to date occurred under Labour he admitted that they had got it wrong. But he then refused to put any figure on the degree of privatisation that would be acceptable in future.

Aside from the Greens, there is only one major party leader who is, rightly or wrongly, committed to a wholly publicly provided NHS and that is Nicola Sturgeon. What an irony it would be if it were to be left to the SNP, in coalition with Labour in Westminster, to draw the line under NHS privatisation in England.