Veteran foreign correspondent John Pilger called on journalists to question how they are being manipulated by the Government over the war.
Pilger, speaking at the Stop the War rally in London’s Trafalgar Square at the weekend, said that it was time for journalists to "take a pride in their craft and stop the propagation of double standards".
The former Mirror foreign correspondent said that it had been one of the greatest accolades of his career to be called "a traitor by Murdoch’s Sun".
Sunday Express journalist Yvonne Ridley, who was taken prisoner by the Taliban, testified to having "met wonderful people in Afghanistan who had now been demonised by the west".
"I visited a village that has since been bombed for three days. That village does not exist anymore, yet there were no Taliban there. Why did they bomb that village?" asked Ridley.
Other journalists addressing the rally included Guardian columnist George Monbiot and writer and broadcaster Tariq Ali.
Police estimated the number of people at the demo as 15,000 while organisers put the figure at 100,000.
The discrepancy prompted supporters of the Stop the War Coalition to write to editors this week complaining that the BBC and the Press Association had not made independent assessments of the size of the crowd.
Instead, the coalition claims, both quoted police figures and misquoted the organisers’ estimates.
By Paul Donovan