The government is about to set out how it wants to change the BBC amid huge tension between the broadcaster and ministers.
The BBC is reportedly furiously lobbying to oppose changes it sees as undermining its independence and compromising its editorial and programming ahead of Thursday, when the Government is expected to announce its White Paper that sets out how it wants to change the corporation.
The White Paper on charter renewal has already prompted outrage.
"It’s not their BBC, it’s your BBC. In many ways our broadcasting - the BBC and also Channel 4, which they’re also trying to eviscerate - is the envy of the world and we should stand up and fight for it," Kosminsky told the audience.
"I think most people would agree that the BBC’s main job is to speak truth to power, to report to the British public without fear or favour.
"It’s a public broadcaster independent of government, not a state broadcaster. All of this is under threat right now.”
Ian Hislop, Private Eye editor and Have I Got News For You captain, said: "The BBC have allowed Have I Got News For You to be rude about governments... and rude about the BBC, which is a privilege you are given with public service broadcasting and not on state television."
The Culture Secretary recently joked that abolishing the BBC was "a tempting prospect".
MP David Lammy called said the Government was "bullying", adding there was "unprecedented bad blood" between them and the BBC.
Here are eight things the White Paper could be about to stop the BBC from doing.
Keep a huge vault of online recipesBBC
Do lighter news storiesBBC News
Make entertainment programmes deemed not 'value for money'Katja Ogrin/EMPICS Entertainment
Give people travel informationBBC
Schedule flagship entertainment at the time flagship entertainment is normally shownAnthony Devlin/PA Wire
Not tell you exactly how much its top talent earnsMatt Crossick/PA Wire
Keep the licence fee to itselfJonathan Brady/PA Wire
Regulate itselfAdrian Dennis/PA Wire