THE dark shadow of dirty tricks and “black ops” has long hung over No 10 during Labour’s time in office, and the machinations are credited with helping to keep the party in power for 12 years.

Both Gordon Brown and Tony Blair have been happy to benefit from the protection afforded by the aggression, ruthlessness and unscrupulousness of their spin doctors.

Once Labour was in government, in 1997, Alastair Campbell, Blair’s press secretary, wielded power that led to him being described as “the real deputy prime minister”. Campbell and Charlie Whelan, then Gordon Brown’s spin doctor at the Treasury, became well known for their tirades against lobby journalists and for briefing against others inside the party.

In 2003 there were calls for the resignation of Tom Kelly, Campbell’s successor, after he falsely described David Kelly as a “Walter Mitty” character in a briefing after the government scientist and nuclear specialist was found dead in a wood.

Last September Damian McBride was forced to move to a less public role after his role in the resignation of Ruth Kelly, the transport secretary, was strongly criticised. At 3.15am on the last night of the Labour conference, McBride briefed journalists that Kelly had asked Brown four months earlier to set her free to spend more time with her children. Labour’s Blairite wing accused Downing Street of triggering a “controlled explosion” to flush out a potential rebel by leaking news of the resignation.

Kelly’s “outing” followed the leaking of names of rebel Labour MPs who had written to ask about the nomination process for a leadership campaign.

A year earlier Downing Street was accused of dirty tricks in trying to defuse the cash for honours scandal exposed by The Sunday Times.

No 10 officials were alleged to have leaked a “killer e-mail” between two of Blair’s closest aides in an attempt to undermine the police investigation. Detectives regarded the e-mail as so sensitive to an alleged case of attempting to pervert the course of justice that they were worried their investigation would be compromised.

The officials were also accused of smearing Angus MacNeil, the Scottish Nationalist MP whose complaint triggered the police inquiry, by passing details of a drunken romp he had enjoyed with two teenage girls to a newspaper.

In 2006 Downing Street was accused of orchestrating a dirty tricks operation after it emerged that it had been passed copies of e-mails sent to David Cameron by his Commons aide. Dave Hill, Blair’s director of communications, was alleged to have played a key role in organising the leak to sympathetic newspapers.

The spin doctors’ biggest coup was in deflecting attention away from Blair’s decision to go to war in Iraq. After the exposure of the “dodgy dossier” of evidence for Saddam Hussein’s weapons of mass destruction and the death of David Kelly, Blair’s inner circle launched a PR war. They claimed three BBC scalps - Gavyn Davies, the chairman, Greg Dyke, the director-general, and Andrew Gilligan, the Today programme reporter - all of whom resigned over the alleged “sexing up” of the dossier on Saddam’s missile capabilities.

Times Recommends

• How I lost the gift of joy for a while
• Why Ann Widdecombe has got it wrong
• Alas, it’s the end of the road for petrolheads