The government has at long last announced a change to Britain’s universal jurisdiction legislation.

A year after Israeli opposition leader Tzipi Livni cancelled a London speech for fear of arrest the Home Office published details of alterations to the law on magistrates issuing arrest warrants for foreign politicians.

The new Police Reform and Social Responsibility Bill includes “a requirement for the consent of the Director of Public Prosecutions to be given before an arrest warrant can be issued in a private prosecution for offences of universal jurisdiction.”

Although the reform will not stop war crimes being prosecuted in this country even if committed abroad by someone who is not a British national, it means that such prosecutions will no longer be at the whim of individual magistrates.

After Ms Livni was forced to pull out of her British trip, and several other Israeli politicians either cancelled appearances or expressed concern about visiting, the then Labour government pledged to change the law but did not do so before their election defeat.

Since gaining power in May the coalition government has also repeatedly promised to amend the law.