Cherie Blair will not be accompanying her husband for most of the general election campaign because of her legal commitments.

The barrister and part-time judge will be engaged on a 14-week court case that has been arranged for a year.

The move is thought to be unprecedented in the era of TV election campaigns.

Party strategists normally like the spouses of party leaders to be seen on the campaign trail in order to establish family credentials and to give candidates the common touch.

Both Ffion Hague and Charles Kennedy's girlfriend, Sarah Gurling, have taken leave from their jobs for the duration of the election.