Henry McLeish resigned as first minister

That process is expected to be a formality - but it comes as newspapers were being warned to act responsibly in their coverage.

Party sources say some editors have gone to ridiculous extremes in pursuit of stories.

One Sunday newspaper is believed to be considering printing an article about Mr McConnell's private life.

However, Mr McConnell's spokesman said allegations involved were completely false.

Last week the education minister held a media conference where he admitted having an extramarital affair with a party colleague seven years earlier.

Labour ballot

It later emerged that he appealed to MPs for cash to help pay the wages of the woman he had an affair with in the early 1990s.

However, Labour insisted that the request for �100 from each MP came from the party as a whole.

Mr McConnell's 54 fellow Labour MSPs and the 29 members of the party's executive will take part in Saturday's ballot at the party's Scottish headquarters.

Before the vote the education minister is expected to make a passionate plea to MSPs for party unity.

If the result is as expected, Mr McConnell is likely to be nominated as Labour's candidate for first minister on Thursday, when a vote will be held in the Scottish Parliament.