BBC News 24 staff could be the first who are to revolt over BBC director general Mark Thompson's planned job cuts.

From Monday, BBC News 24 staff will refuse to work beyond their contracted hours or cover for staff shortages as part of a protest against the 4,000 job losses announced by the BBC last month.

The corporation said it was "confident" it could maintain the quality of News 24's output during the action.

A BBC spokesman said: "We are disappointed that the NUJ has sent out this instruction before the official ballot. However, we are confident we can maintain News 24's usual high quality service for our audience."

The NUJ letter detailed the action staff would take. "Staff have been asked to stop acting up. They do not get paid for it and it is not part of their contract," it stated.

"Staff are being advised to take their full break allocation. As you know, when things are busy, staff often stay at their desks. We don't think this is acceptable on health and safety grounds. We will also be insisting that all staff get their entitlement to five minute screen break each hour regardless of the pressure of work," Mr Serpell said.