The terrorists El Shafee Elsheik and Alexanda Kotey would have been brought to justice more easily under an updated treason law, according to the Policy Exchange think tank

Britain’s ancient treason laws should be revived and brought up to date to allow terrorists to be jailed for life, MPs and academics recommend.

A report whose authors include Tom Tugendhat, the Conservative chairman of the foreign affairs committee, and Khalid Mahmood, the Labour MP, says that citizens who betray the country through acts of terrorism should be dealt with as traitors.

The report from the Policy Exchange think tank suggests that a treason law would have made it easier to bring to justice members of the so-called Beatles group of Islamic State terrorists who the government wants to send to America for prosecution.

Tom Tugendhat, chairman of the foreign affairs committee, wants terrorists to be treated as traitors VICTORIA JONES/PA

Treason laws, which date back to 1351, are still on the statute book but are not considered a viable law