BBC workers have protested against political "pressure and interference" in the wake of the Hutton report.
BBC staff protested at offices across the UK
Hundreds joined a demonstration outside Television Centre in west London and further rallies were held at offices including Glasgow, Cardiff and Bristol.
Organisers the National Union of Journalists and broadcasting union Bectu said they wanted to challenge any attempt to curb the BBC's independence.
The BBC was criticised in the report into the death of Dr David Kelly.
It led to the resignation last week of Chairman Gavyn Davies and Director General Greg Dyke.
Today programme reporter Andrew Gilligan, whose controversial story alleging the government "sexed-up" its dossier on Iraqi weapons was called "unfounded" by Lord Hutton, also stepped down.
NUJ general secretary Jeremy Dear told BBC News Online the protests would send "a very vocal message to the government and governors".
September 2002: Government produces dossier about alleged Iraqi weapons of mass destruction, including claim they could be deployed within 45 minutes
May 2003: BBC Today programme's Andrew Gilligan broadcasts report of claims Downing Street "sexed up" dossier, with 45 mins claim included against intelligence agencies' wishes
10 July 2003:Dr David Kelly named as suspected source of report as government continues to deny the story
17 July 2003: Dr Kelly found dead
August 2003: Lord Hutton begins six weeks of hearings about the circumstances around Dr Kelly's death
He described the action as the start of a campaign to protect the independence and funding of the BBC, as well as the right to carry out investigative reporting.
"It is important to give confidence back to staff - that is an immediate concern as they have a right to report," he said.
Labour MP Austin Mitchell told the crowd he had seen "many wars" between the government and the BBC, "but never one as bloody or dictatorial as this".
Carol Malia, who presents the Look North evening news programme, was involved in a protest at the BBC's studios in Newcastle.
She said: "Any news organisation has to be seen as impartial to be credible and that is what we are fighting for."
Mike Baker, an education correspondent in London who
has worked for the BBC for 24 years, said staff wanted to make a "symbolic" protest.
He said the corporation had made mistakes, but that the Hutton report "was not balanced" and "failed to take into account the amount of intimidation going on towards the BBC".
Commenting on the departure of Greg Dyke, Alison Johnston, from the BBC's rights department, said: "He was a great communicator and very open to new ideas from the staff and treated all of us equally, from the bottom to the top."
Thousands of staff staged impromptu walkouts last week in support of Mr Dyke following the release of the Hutton report's findings.
Many also paid for an advert in a national newspaper supporting their former director general.
Mark Byford, acting director general, has said the corporation recognised it had made errors in its reporting of the government's handling of intelligence on weapons of mass destruction in Iraq..
He is leading an internal investigation into the failings highlighted by Lord Hutton in the BBC's editorial procedures.
The lunchtime protests were held after BBC governors denied claims made in the Independent newspaper on Thursday that they had spurned lawyers' advice that the Hutton Report was legally flawed.
A spokesman for the governors said: "There is no question that the BBC's Board of Governors ignored legal advice."