'It has been said 'as long as Commercial Radio is there, Albert Cheng is there'. But there is no longer a basis of mutual trust,' he said.

Cheng, who survived a chopping attack in 1998, which he believed was in response to his outspoken remarks, said he had never thought he would be removed by his on-air 'family' and that he no longer felt its 'comfort and protection'.

But he said: 'She [Winnie Yu] made my wife the happiest woman today. I have to thank her for that.' Mrs Cheng has wanted her husband to quit the airwaves since the attack.

Ms Yu, who spoke to Cheng on Commercial Radio's evening programme, denied sacking the veteran talk-show host. She later said the radio station was 'not under any political or commercial pressure' to end Cheng's contract.

Cheng is due to appear this morning on Teacup in a Storm, the current affairs phone-in programme he has hosted for 10 years.

Speculation has been rife that he is being forced out of the show. He has been on leave since May after he complained of political pressure and intimidation.

Earlier yesterday, in response to calls for clarification in a newspaper advertisement by Cheng's supporters, Ms Yu told Teacup in a Storm that negotiations for an early settlement of Cheng's contract were in progress.

She said that by running away one after another, programme hosts were themselves undermining freedom of expression, while the broadcaster was committed to acting as a platform for defending it.

'As the manager of this platform, we are helpless and have played no part in discussing how to face the challenges ... In a way we are seen as accepting Hong Kong as having no freedom of expression. This is just unacceptable,' she said.

Cheng's co-host and longtime ally Lam Yuk-wah had also indicated his wish to leave with Cheng and 'put the era to an end', Ms Yu said.

She also criticised Wong Yuk-man, another host known for his sharp attacks on the Tung administration, for running way without notice. 'This is absence from duty, a great taboo. The show must go on.'

She said she particularly regretted the departure of political heavyweight Allen Lee Peng-fei, saying she had held very high hopes for him as a stand-in for Cheng.

With Hong Kong undergoing a difficult period, Ms Yu said the programme needed a thorough review of its style to keep abreast of the times.

'We have decided not to resort to airing emotional expression. Instead, we will take a rational approach to deal with issues. The more difficult the situation Hong Kong faces, the more we need to keep control of our emotions.'

Cheng said it was unfair to blame run-away programme hosts for not defending freedom of speech. 'My going off air [in April] was not a withdrawal. I was not irresponsible and did not undermine freedom of speech.'

He said the top management had never indicated they were unhappy with his taking leave, and he would not have gone if warned beforehand that it would be seen as an act of cowards and deserters. It was not until late June that he was told about the early termination of his contract, with no reason given.

Mr Lee said he would also sever ties with the radio station. 'I believe [Ms Yu's] treatment of Taipan, who did so much work for the station for so many years, was very unfair. She didn't have to say so many things when she was trying to end his contract,' he said.Writing on a Commercial Radio website message board, someone using the name of Wong Yuk-man said he believed he would face the same fate as Cheng.

But this would not mean the end of his career, Wong said. He said he was doing fine and was awaiting an operation, but did not elaborate.