Chris Stephen: Human rights are taking a beating in name of politics

The announcement, made in Jerusalem by Foreign Secretary William Hague, will allow the government to veto war crimes prosecutions against visiting officials from Israel or any other friendly nation.

As such, it changes not just British war-crime law but also legal custom and practice, which holds that anyone has the right to bring a criminal charge before a magistrate.

The laws in question are Britain's commitments under the Geneva and Torture conventions to try war crimes suspects no matter where the alleged crimes were committed - the principle of universal jurisdiction.

These laws, and the right of individuals, not just the state, to bring a prosecution have been used in recent years by pro-Palestinian groups in the UK to launch unsuccessful attempts to arrest visiting Israeli dignitaries.

The day before Mr Hague's visit to Jerusalem this week, Israeli intelligence minister Dan Meridor announced Israel may suspend intelligence co-operation with Britain due to the risk he and colleagues run if they visit the UK.

Mr Hague's argument is current British law allows spurious "politically motivated" prosecutions to be brought by rights groups to embarrass visiting officials, and the Director of Public Prosecutions needs to be deployed as a gatekeeper.

This is bunkum. The gatekeeper role is already performed by judges, who only issue arrest warrants if presented with a primae facie case. Mr Hague said as much when he assured Israel the new law would mean blanket immunity from prosecution, seemingly regardless of the merits of any case brought against a visiting official.

Israel is right in insisting it is being singled-out by rights groups for universal jurisdiction arrest warrants in the UK; scores of officials from states with more egregious human rights records than Israel pass through London each week and there is no line of human rights groups waiting to snare them. But that is no reason to junk the law, not least because Britain has, until now, been a pioneer in developing war crimes justice.

But as international justice has grown in scope, so the big powers have begun to agitate. Last year, Spain amended its own universal jurisdiction law to make prosecutions harder after pressure from China, Israel and the US, who were riled by investigations into Tibet, Gaza and Guantanamo Bay.

Rights groups are clinging to the hope the proposed bill may have a rough passage through parliament. The Justice Ministry, meanwhile, has been taken by surprise by Mr Hague's remark that the new law will be unveiled "within weeks" as it has not yet circulated a draft bill.