I lied, it went in 1998.
After abolition of the death penalty for murder, die-hards began a tradition requiring the Commons to hold a free vote on a motion during each Parliament proposing the restoration of capital punishment. This motion was always defeated. However, the death penalty still survived for other crimes, namely:
causing a fire or explosion in a naval dockyard, ship, magazine or warehouse (until 1971);
espionage[5] (until 1981);
piracy with violence (until 1998),
treason (until 1998), and
certain purely military offences under the jurisdiction of the armed forces, such as mutiny[6] (until 1998). Prior to its complete abolition in 1998, it was available for six offences: 1) serious misconduct in action, 2) assisting the enemy, 3) obstructing operations, 4) giving false air signals, 5) mutiny or incitement to mutiny, and 6) failure to suppress a mutiny with intent to assist the enemy.
However, no more executions were carried out under UK law.
4) giving false air signals, Christ the times I`ve done that after a few bevvies. You just dont realise do you ?