Mr Fairweather is seeking reappointment

But Mr Fairweather, a critic of private sector involvement in the prison service, told BBC Scotland that he would be among the 33 applicants seeking the �50,000-a-year position.

He said: "It's correct. I have applied, but I don't think it's right to talk about it."

Asked how he rated his chances of success, he declined to comment.

Derek Turner, assistant secretary of the Scottish Prison Officers' Association said the decision to try to replace Mr Fairweather was politically motivated,

He said: "The best I could say about Clive is he's always been fair to the prison service.

"He's always been quite happy to highlight problems where they existed but equally to highlight centres of excellence where they existed. So overall he's just been very fair.

'Fair and open'

"I think there's certainly been some political agenda since Clive mentioned the fact the Kilmarnock (privately run prison) was a failing experiment.

"I certainly think that it is perhaps high on the agenda to get rid of Clive because of his comments on the private sector."

A spokeswoman for the Scottish Executive said: "Mr Fairweather is entitled to apply for the position.

"As in all cases the principle of fair and open competition will apply."

Mr Fairweather has held the post since 1994 and has twice had his contract extended.