In my experience of these things, parties which shout about dirty tricks and the like tend to do so because they fear a direct hit in some vulnerable part of their political anatomy.

In 1986 Mandelson ran the campaign at the Fulham by-election in which Labour defeated the Conservative Party. The protester was cautioned on 9 April for causing "harassment alarm or distress". This prompted him to make an exuberant acceptance speech which was televised live in which he declared that "I'm a fighter not a quitter" and referred to his "inner steel".

After his second resignation he served as the European Commissioner for Trade from 2004 to 2008. He is President of the international think tank Policy Network. He was a key architect in the rebranding of the Labour Party as "New Labour" and its subsequent landslide victory in the 1997 general election.