Prime Minister Gordon Brown has announced an imminent change in universal jurisdiction law, as predicted exclusively by the JC last week.

Mr Brown said the law has been exploited for “political gains”. The move is believed to be a direct response to a leader comment in the JC urging government action. Mr Brown was shown the piece by pro-Israel MP and close ally Tom Watson.

Mr Watson is reported to have wanted to demonstrate to Mr Brown the strength of feeling about the issue in the Jewish community.

The current law, which allows visiting foreign officials to be arrested for war crimes if a magistrate grants an arrest warrant, caused the former Israeli Foreign Minister Tzipi Livni to cancel a trip to London late last year after an arrest warrant was issued.

Mr Brown proposed that the Crown Prosecution Service should take the responsibility for prosecuting for war crimes.

Writing in the Daily Telegraph, Mr Brown said: “It is our moral duty to ensure that there is no hiding place for those suspected of the most serious international crimes.

“Britain will continue to take action to prosecute or extradite suspected war criminals – regardless of their status or power.

But he raised concerns over the flimsy evidence which could be used to issue an arrest warrant against a visiting official, like Ms Livni, which only serves to make a political point.

He wrote: “As we have seen, there is now significant danger of such a provision being exploited by politically-motivated organisations or individuals who set out only to grab headlines knowing their case has no realistic chance of a successful prosecution.

“Men and woman can then be held in prison on the basis of 'information', when the serious nature of such cases means that in any event they can only proceed to prosecution with the consent of the Attorney General.”

Referring to the cancellation of Ms Livni’s visit, Mr Brown said: “There is already growing reason to believe that some people are not prepared to travel to this country for fear that such a private arrest warrant – motivated purely by political gesture – might be sought against them.”

Making war crimes arrests the domain of the CPS would strengthen universal jurisdiction, Mr Brown said, because arrest warrants would then only be issued for those against whom there was a credible case.

The Conservative Party has said it will vote with the government on the law change but the government fears a rebellion on its own benches. An early day motion opposing a change to the law has now been signed by 123 MPs.