Zacarias Moussaoui is serving six life terms for the 9/11 attacks

Britain secretly abandoned its opposition to the death penalty to hand over information linked to the prosecution of a 9/11 suspect when Lord Blunkett was home secretary, The Times has learnt.

Despite public criticism of capital punishment, Britain offered “mutual legal assistance” in the case of Zacarias Moussaoui, the so-called 20th hijacker, who was accused of plotting nearly 3,000 murders in September 2001.

In July this year, Lord Blunkett, the Labour home secretary between 2001 and 2004, criticised the government’s decision to waive death penalty assurances to help a potential US prosecution against Alexanda Kotey, 34, and El Shafee Elsheikh, 30, the alleged Islamic State killers known as the Beatles.

The pair, both from London, are suspected of being two of the four Isis members