In the wake of the deadly London Bridge terror attack, far-left Labour Party leader Jeremy Corbyn said that terrorists should “not necessarily” serve their full prison sentences.

Corbyn, who has a history of sympathising with IRA terrorists, said that he believes the length of prison sentences for terrorists “depends on the circumstances” and “what they’ve done in prison”.

Asked whether convicted terrorists should “not necessarily” serve their full prison terms, Corbyn told Sky News “not necessarily, no”.

“I think there has to be an examination of how our prison services work and crucially what happens to them on release from prison because I need to know whether or not the Parole Board were involved in his release. Apparently, they were not. They made that statement quite quickly after the release… after [Friday’s] terrible incident,” said Corbyn in a programme aired on Sunday.

“Secondly, there was apparently no probation service involvement in monitoring this former prisoner who, after all, had only served half his sentence and he came out I think a year ago. There has to be an examination of what goes on in the prison because prisons ought to be a place where people are put away because of major serious offences but also a place where rehabilitation takes place,” he added.

On Friday of last week, Usman Khan, a convicted terrorist who was freed from prison on an electronic tag, went on a rampage on London Bridge, killing two.

Khan’s lawyer has since expressed concern that Mr Khan may have lied to him and others while in prison to get his release, by pretending to have been deradicalised.

Prime Minister Boris Johnson expressed his anger over the release of Khan, blaming the terrorist attack on a “broken hung parliament” that was “preoccupied with blocking Brexit” and the policies of the Labour government under Gordon Brown.

“The terrorist who attacked yesterday was sentenced 11 years ago under laws passed in 2008 which established automatic early release,” Johnson said.

“This system has got to end — I repeat, this has got to end, as I’ve been saying for four months. If you are convicted of a serious terrorist offence, there should be a mandatory minimum sentence of 14 years — and some should never be released,” he concluded.

A new Sentencing Bill was introduced as a part of the Queen’s Speech in October. However, it was not put into place before the general election was called. The new bill would have raised the automatic release time to two-thirds of the sentence, up from half.

Judges have discretion in extending sentences for convicts who they deem to be dangerous, but the proposed Sentencing Bill would have made longer prison terms mandatory for certain crimes.

Follow Kurt on Twitter at @KurtZindulka