The immediate trigger for Michael Heseltine’s resignation from the Cabinet over Westland in 1986 was Margaret Thatcher’s refusal to risk a debate on the issue in the full Cabinet after losing the argument in a Cabinet committee.But Mr Heseltine says in the programme that he thinks she would probably have won if it had been debated by the full Cabinet. Ministers across the political spectrum frequently attest to the degree of ideological unity in government.Further, the recent reforms to the Cabinet office by Sir Richard Wilson, the Cabinet Secretary, were widely seen as strengthening the grip of the centre on the departmental baronies – even to the extent that some officials have even suggested that they will help to usher in a more “Napoleonic” system of government. The “kitchen cabinet” of the unelected advisers to both the Prime Minister and to some extent the Chancellor of the Exchequer, seem more powerful than most junior or middle ranking Cabinet ministers.A strong prime minister can indeed wield huge authority over his Cabinet colleagues, even on a policy issue in which he or she is facing strong opposition. On the face of it, of course, this seems a mere technical point.If ever there was a time when a prime minister can order his ministers to do more or less what he wants them to, it is now.

His popularity, his authority in his party, his media image of sheer indispensability all make him a frighteningly formidable adversary for a Cabinet dissident. His power may be informal; but that doesn’t make it any less real.At present the idea of loose, collegiate, Cabinet government a la John Major or Jim Callaghan could not seem more remote. There is precious little sign of the full-scale internal debate within the Cabinet which feature on the pages of the Crossman or the Barbara Castle diaries. Never mind that he has many fewer formal powers than Jacques Chirac or Boris Yeltsin or Bill Clinton; he cannot even issue a circular to local education authorities as David Blunkett can.
As Jack Straw, the Home Secretary, points out in this week’s programme in the BBC Radio Four series Matrix of Power, an individual secretary of state’s authority rests partly on the fact that his or her name, and not the prime minister’s, is on the big Bills going through Parliament. The sole circumstances under which he has truly prime ministerial power would have three minutes to last. Unlike the secretaries of state, who have a host of statutory powers, duties and discretions, he has none. This graphic point is made by Professor Peter Hennessy to illustrate the formal limits of the prime minister’s executive authority in the British system.

Nothing surprising here, except that, apart from hiring and firing his ministers, it is more or less the only executive action which a prime minister is entrusted by the constitution to carry out on his own. IMAGINE BRITAIN under nuclear attack. Only one man – or woman – can authorise the Chief of Defence Staff to give the order for the retaliatory launch of Trident Cruise missiles: the Prime Minister. The Welsh no doubt kicked someone else out when they first got to Wales The Irish, perhaps.