MPs from across the political spectrum told the government today that it must back the International Criminal Court in its actions against Israeli war crimes.

In a letter to Foreign Secretary David Cameron, more than 100 parliamentarians — MPs and peers — urged “the UK government to do all it can to support the International Criminal Court” in its work.

The letter, organised by Labour MPs Richard Burgon and Imran Hussain, came as the government continued to dismiss the decision of the court’s chief prosecutor to seek arrest warrants for Israeli Premier Benjamin Netanyahu and Defence Minister Yoav Gallant, as well as Hamas leaders.

Another Labour MP, Zarah Sultana, added to the pressure, using Prime Minister’s Questions (PMQs) to demand that Rishi Sunak commit to arresting Mr Netanyahu should he visit Britain, as well as ending arms sales to Israel in order to uphold international law.

Mr Sunak made no such commitment but European Union foreign policy chief Josep Borrell made it clear today that all the bloc’s member states would be expected to execute the arrest warrant on Mr Netanyahu should the opportunity arise.

“All states that have ratified the ICC’s statutes are bound to executive the court’s decisions,” he wrote. 

Nearly all European countries, in or out of the EU, have ratified the court, which limits Mr Netanyahu’s travel possibilities in the continent going forward, should the warrants be eventually issued.

The letter to Lord Cameron also called on him to “condemn any threats and attempts to undermine the independence and impartiality of the International Criminal Court in its investigations into crimes in Gaza” when such moves are being advocated in the United States Congress.

The signatories point out that “there is mounting evidence that Israel has committed clear and obvious violations of international law in Gaza and [we] strongly believe that those responsible must be held to account.”

Any attempt to obstruct the court’s work would “not only undermine accountability for atrocity crimes committed in Gaza but would weaken the rule of law and international justice as a whole,” they added.

Mr Burgon, a former shadow justice secretary, said: “While our government has rightly condemned the war crimes committed by Hamas on October 7, it has repeatedly refused to condemn the war crimes committed by Israel in Gaza. 

“At every stage, our government has failed to fulfil its moral duty to do everything it can to help save lives and prevent suffering in Gaza.

“It must back the ICC in ensuring that there is no impunity for war crimes and it must stand up to those seeking to impede justice.”

Mr Hussain said that the prosecutor’s decision “to pursue arrest warrants for war crimes carried out since October 7 is a vital step towards securing justice for the victims.

“It is clear that Israel is carrying out war crimes and our government must take a stance for the rules-based order and insist on accountability for those perpetrating war crimes.

“That is not only key to securing justice but also in helping prevent more crimes.”

The government was also urged to emulate Ireland, Norway and Spain, which today announced that they were recognising a Palestinian state, much to Israel’s displeasure. 

Neither the government nor Labour are committed to doing as much at this stage.

Campaign group Momentum urged Labour leader Sir Keir Starmer to break from this consensus.  It said today that the three European countries had “demonstrated courageous leadership.”

The group added: “As the UK government continues to fail the people of Palestine, it’s vital the next Labour government commits to step up and recognise a Palestinian state.

“Amid Israel’s carnage in Gaza, the time for warm words and empty promises is over."