Scottish Secretary Helen Liddell and First Minister Henry McLeish were overheard making less than flattering assessments of the Northern Ireland Secretary, Dr John Reid, and the Foreign Office Minister, Brian Wilson, before a news conference on Friday.
A journalist from radio station ScotFM recorded the remarks during an unguarded moment before the press conference.
Mr McLeish can be heard describing Mr Wilson as "a liability".
He is also heard describing Dr Reid, as "a patronising bastard".
A spokesman for Mrs Liddell said the comments had been made ''first thing this morning after a long election campaign in which everyone was tired''.
It will once again raise questions of the relations between UK and Scottish Executive ministers and is all the more embarrassing coming as Labour celebrates its re-election landslide.
Labour appeared to have seen off reported divisions between the Scottish Executive and the Scotland Office which surfaced when Donald Dewar and Dr John Reid held the respective posts.