The pressure followed newspaper reports Mr Whitton had belittled Mr Dewar's Scottish Executive colleagues when defending the first minister's record.

BBC Scotland Political Editor Brian Taylor: "Controversy sparked by defence of Dewar"

Mr Whitton had flattened suggestions Mr Dewar might be replaced but in the process was accused of playing down the capacity of other ministers to lead the parliament.

In an unusual move, Mr Dewar issued a statement in an effort to close the matter, praising his aide's "professionalism and integrity" as chief media spokeman.

David Whitton: Facing accusations

He insisted he would continue in his post and in an effort to soothe any wounded pride among colleagues, said his ministerial team combined energy and ability.

Mr Dewar said: "I have a ministerial team which combines energy and ability and I value the contribution of every member of it. Whatever our past experience, we are all new players in a new system.

"David Whitton is and will continue to be my press spokesman.

"He has worked very closely on my behalf with journalists in every part of Scotland, his professionalism and integrity are unquestioned."

But opposition parties seized on the statement as further proof of disarray within the Scottish leadership.

Alex Salmond: Doubts over ministers

Scottish National Party Leader Alex Salmond said Mr Dewar's decision to back Mr Whitton sent a clear message to Labour ministers.

He said: "In choosing to back him - against the wishes of others in the Labour Party - Donald must therefore agree with his spokesperson's views that the Scottish Executive members are 'unproven and unqualified'.

"We are now in the extraordinary position of having a first minister who appears to believe that the 21 other members of his administration are barely up to the job."

Scottish Tory Leader David McLetchie said: "Donald Dewar's vote of confidence in David Whitton is tantamount to a vote of no confidence in his ministerial team."