Senior executives who support his changes came to his aid yesterday as the pressure grew for him to resign because of the controversy over his tax arrangements.
All 10 fellow members of the board of management, which runs the BBC's day-to-day affairs, signed a letter published in the Times today calling for him to continue as Director-General.
And in another letter six well- known BBC journalists accused Mr Birt's critics of settling old scores. Martyn Lewis, the Nine O'Clock News presenter, Peter Sissons, the Six O'Clock News presenter, Peter Jay, the economic editor, Robin Oakley, the political editor, Polly Toynbee, the social affairs editor, and John Simpson, the foreign affairs editor, pledge their support for Mr Birt.
They say Mr Birt was guilty only of a hastily-corrected error of judgement which applied equally to the BBC governors who agreed his financial arrangements.
The letter says Mr Birt's critics are trying to destroy him in order to destroy his radical plans.
The letter from the senior management states: 'The controversy surrounding the employment arrangements of John Birt has obscured the major issue in British broadcasting - the future of the BBC beyond 1996 when its current Charter expires.'
It adds that broadcasting will change substantially in the next few years and the BBC must 'have a clear vision if it is to retain its role as the cornerstone of British broadcasting and continue to command respect and admiration in Britain and throughout the world.
'In January John Birt laid out that vision of a wide range of high- quality programmes, greater efficiency and accountability with value for money for licence payers. We, the ten members of the Board of Management, believe that John Birt is the best person to lead the BBC and he has our unanimous support.'
Two of the signatories had already publicly supported Mr Birt before the letter was distributed by the BBC press office yesterday. Will Wyatt, managing director of network television, backed him in a radio interview while David Hatch, an adviser to the Director- General, delivered his support in an article in the Sunday Express.
This concerted campaign to shore up Mr Birt's position came as pressure increased for him to resign over the revelation that his BBC salary had been paid into his private company.
The executives' public support was in sharp contrast to the silence of the BBC governors.
James Fenton, page 21