Joe Haines, a pioneer of political spin, has announced he is tearing up his Labour Party membership card after more than 40 years.

Haines, who was Downing Street press secretary to Harold Wilson, criticised Tony Blair's administration as a "flat-pack government" and slammed its U-turns on university top-up fees and the referendum on the proposed European constitution.

The departure of such a well-known figure will be a psychological blow to the party, as it struggles through one of Blair's most difficult periods since gaining power.

"After his second sweeping election triumph in 2001, Tony Blair promised bold government. Bold? Palsied would be a better description of it," Haines wrote in the Mail on Sunday.

"At last year's Labour conference, the prime minister boasted that he had no reverse gear. If he hasn't, he's got a sideways gear, plus one which cricketing buffs would recognise as going in the direction of deep third man."