For the past 25 years, it has been Labour Party policy that what Britain needed was not just a slimmer, less ferocious Official Secrets Act, but a positive public right to know, enshrined in a Freedom of Information Act.
John Major took a step towards this in 1993-94 when his Open Government White Paper and the code based upon it established the principle of access to official information, subject to certain exemptions. Though this fell well short of a statutory Freedom of Information (FOI) regime, the Ombudsman was invited to police the code and arbitrate disputes. For the first time, an independent figure outside Whitehall was involved in disclosure decisions.
Mr Major and his open government minister, William Waldegrave, also performed a specially important service for contemporary historians such as myself in establishing a review procedure to re-examine all files retained beyond the 30-year norm laid down by the Public Records Act 1967. Thanks to the so-called "Waldegrave Initiative", nearly 100,000 files have since been released, many of which, particularly those related to intelligence and nuclear matters, are - or were - of an especial sensitivity.
Mr Major and Mr Waldegrave deserve great credit for this - as does Douglas Hurd, just about the only senior figure in the Major cabinet who backed them.
So what of Labour? Today's Cabinet grew up with an FOI mantra. Indeed, I first met some of them when they were engaged on the committee stage as true believers in Clement Freud's Freedom of Information Bill, which fell when Parliament was dissolved after the Callaghan administration lost its vote of confidence in 1979.
I always wondered if the bloom of openness might not fade when confronted by the discreet pleasure of the Red Boxes that come with high office. In private, in the run-up to the 1997 election at seminars involving senior civil servants and others, I would unfold a kind of malign vision of New Labour suddenly discovering the attractions of closed government with the promised FOI Bill somehow slipping out of the first Queen's Speech, then the next ...
In December 1997, however, I was confounded. A White Paper, Your Right to Know, announced the Government's intention to construct just about the most liberal FOI regime in the advanced world. For many areas, a "substantial harm" test would be applied to information which, if not met in the judgement of an independent and robust Information Commissioner, would see that information released into the public domain.
Though I still didn't quite believe it, I was pleased to be shown up as a jaded old pessimist. Now my Whitehall friends wonder how I could have been so Pollyanna-like. Jack Straw grabbed the lead on FOI after last summer's reshuffle and dragged it out of the Cabinet Office into the Home Office
Equally important is that both the Prime Minister and his Cabinet secretary, Sir Richard Wilson, thought the original White Paper would not do. Their influence pervaded the Cabinet committee rooms where the gelding took place. As one of his ministers said, the two most powerful words in Whitehall are "Tony wants".
In this case, Tony most definitely did not want. Lord Irvine of Lairg, the Lord Chancellor, in the chair of the FOI Cabinet Committee (the only one I can recall in recent times that is larger than the Cabinet, so keen were departments to preserve their secret gardens) could not resist the Blair-Straw-Wilson combination.
So there it was last month, a draft Bill - a sorry, shorn thing. Gone was the "substantial harm" test. In its place was a "prejudice" test. And who will certify that information disclosed "would be likely to prejudice the policy making or decision-taking processes"? Why, ministers of course. There are even regressions in Straw's draft Bill from Mr Major's code, not least on public records. The Major document, for example, reduced to 30 the 100 year norm for Whitehall files dealing with Buckingham Palace matters. Somehow in the draft Bill this has slipped back to 75 years.
I shall never again succumb to Pollyanna-isms. We have in Mr Blair, as one of Mrs Thatcher's ministers once said of her, "a prime minister who does not believe in open government for the cabinet, let alone for people like you!"
The writer is professor of contemporary history at Queen Mary and Westfield College, University of London