Thousands of BBC journalists, technicians and other staff are staging a nationwide protest across Britain at the "attacks" on the Corporation following the Hutton Report.
Demonstrations are due to be held outside BBC offices and studios in a bid to challenge any attempt to weaken the organisation's independence.
Journalists also wanted to show their support for Greg Dyke, who resigned as director-general last week in the wake of Lord Hutton's findings.
There were impromptu walk-outs by thousands of workers last week amid widespread anger at the report's findings, but today's demonstrations were organised by the National Union of Journalists and the broadcasting union BECTU.
One of the biggest protests is expected at the BBC TV Centre in west London, where Labour MP Austin Mitchell will speak to journalists.
NUJ general secretary Jeremy Dear said: "The Hutton Report poses a real and grave threat to journalism. It will inevitably mean that journalists face greater pressure to reveal their sources and it will make sources and whistle-blowers think twice before coming forward."
Mr Dear said that the "abject apology" from the BBC governors had given succour to politicians and others who wanted to influence the news agenda.
PA