The US has been accused of putting pressure on the new Labour government not to drop a legal challenge mounted by Rishi Sunak’s administration over the international criminal court’s right to seek an arrest warrant against Benjamin Netanyahu for war crimes.

In May, under the previous Conservative government, the Foreign Office challenged whether the ICC had any jurisdiction over Israeli actions in Gaza. In 2021, the ICC ruled that it did have jurisdiction over Israeli activity in Palestine.

The ICC has given the new Labour government until 26 July to decide whether to pursue the legal challenge. It did so after the ICC pre-trial chamber ruled on 26 June that it would allow the UK and other interested parties to make submissions over the jurisdiction. Other states and interested parties have been given until Friday to make their own submissions to the court.

The human rights barrister Geoffrey Robertson makes the claim about US pressure on Labour in a Guardian article published on Wednesday in which he also warns that giving into US pressure would be “the first big moral mistake” of the premiership of Sir Keir Starmer. He writes: “The US is not a member of the ICC, and expects the UK to look after its interests there.”

The issue of the ICC request for an arrest warrant was expected to be raised at a meeting between Starmer and the US president, Joe Biden, in Washington, the first between the two men.

Labour officials at the weekend told the Guardian that in opposition Labour had rejected the Conservative legal challenge to the ICC jurisdiction and its policy remained unchanged in government, but did not say if the claim was being withdrawn as a result.

The UK foreign secretary, David Lammy, is expected to travel to the region on Monday to face what may be tough scrutiny of Labour policies, including on arms sales.

The Foreign Office’s argument to the ICC, first propounded by Israel, is that the Oslo accords agreed between Yasser Arafat and Yitzhak Rabin from 1993 to 1995, reached with the help of Norwegian mediators, preclude Palestine from prosecuting Israelis.

Describing the legal argument as preposterous, Robertson points out: “The ICC decided in the 2021 case that this was ‘not pertinent’ to its right to punish crimes in Gaza as Palestine was a member state, so any war crime on its territory fell within the ICC’s remit.”

Robertson writes: “The ICC was not even in existence in 1995 (it was not established until 2002), and the idea that a provisional clause in a moribund negotiation 30 years ago can prevent it from acting over breaches of international criminal law now is preposterous.

“Israel’s argument, adopted (so far) by the UK, is that Palestine is precluded from prosecuting Israelis and this means it cannot ‘delegate’ such prosecutions to the ICC. This is wrong because the ICC prosecutor is in no sense a delegate of Palestine.

“Karim Khan KC is an independent prosecutor who has collected evidence that he will bring to the court to ask it to issue an arrest warrant. He has no connection with Palestinian authorities.

“If the argument adopted by the UK is correct, there would be nothing to stop the Israel Defense Forces lining up Palestinian children and executing them point-blank. There would be no accountability for any crime against humanity they might commit.”

Due to the legal challenge, no ICC decision on issuing arrest warrants is likely until August at the earliest.