In fact, since 1997, there has not been cabinet government in Britain. Power is centralised around the Prime Minister's informal entourage and patronage is used ruthlessly to keep people in line. The Prime Minister does not hold himself responsible to Cabinet or Parliament but to the media, which is why Alastair Campbell and Peter Mandelson have been so powerful.

Under the Blair regime, much more than under Margaret Thatcher, British constitutional arrangements are crumbling. The votes of one in four of the people in the 2001 election produced a majority of 64 per cent in the Commons. This means almost anything can be rammed through the Commons and the only resistance comes from the House of Lords. Power has been sucked into No 10 and policy is driven by headline-grabbing announcements. It means that checks and balances have broken down, and that leads to ill-considered policy - most tragically in Tony Blair's policy towards Iraq.

http://argument.independent.co.uk/commentators/story.jsp?story=542347