The Free Software Foundation (FSF) is planning protests at key BBC sites because it believes the national broadcaster's management has been corrupted by Microsoft.
Protests will be mounted outside Television Centre in London and outside the corporation's Manchester offices on Tuesday, 14 August.
The activists' move has been sparked by increasing concern over the Windows-only, Internet Explorer-only beta release of iPlayer, the BBC's on-demand application.
A Downing Street website petition calling on Gordon Brown to raise the issue in Parliament has been signed by more than 13,000 people as of writing.
In particular, the FSF says the appointment of Erik Huggers, the former director of Microsoft's Windows digital media division, as the BBC's controller of the future media and technology group in May this year, is evidence of Redmond-driven corruption of the BBC's core values.
In a statement, the FSF said: "They have given Microsoft complete control. BBC programming is in the hands of a US based corporation, and the BBC has given up the fight for open access." The group calls on BBC director general Mark Thompson to "clean up the mess he has made" over the iPlayer.
The FSF has long pursued an agenda against Digital Rights Management (DRM), which the BBC says iPlayer must incorporate so it can legally distribute third party programming.
The BBC Trust, which is the corporation's independent governing body, met with representatives from the Open Source Consortium (OSC) to discuss their insistence that the iPlayer should be made available on all platforms as soon as possible, regardless of DRM. More than a week later, BBC management have yet to respond to the trust's call for them to liaise with the OSC, however.
The BBC did not immediately respond to a request for comment on the protests. The FSF's pages on its action are here. ®