A pro-Israel legal advocacy group has written to the government threatening action over the decision to suspend around 30 licences for arms exported to Israel.

UK Lawyers for Israel (UKLFI) has questioned the criteria on which the government based its decision.

Jonathan Turner, the chief executive of UK Lawyers for Israel, said: “We consider that there is a strong case that the government’s decision was unlawful.

"In truth, it was a political decision to appease members of the public who hate Israel based on misinformation and biased media coverage of the war. As such, it was a misuse of the power granted by the legislation.”

According to the government, its decision to ban some arms licences was based on a recommendation of the Strategic Export Licensing Criteria (SELC), which says that the government should “not grant a licence if it determines there is a clear risk that the items might be used to commit or facilitate a serious violation of international humanitarian law.”

Speaking to the House of Commons on Monday, British Foreign Secretary David Lammy announced that the government would halt some arms sales to Israel based on this clause.

Lammy said that government “have not and could not arbitrate on whether or not Israel has breached international humanitarian law”, but that it had a legal duty under the Strategic Export Licensing Criteria not to grant an arms export licence “if it determines there is a clear risk that the items might be used to commit or facilitate a serious violation of international humanitarian law”.

He said: “The assessment I have received leaves me unable to conclude anything other than that for certain UK arms exports to Israel, there does exist a clear risk that they might be used to commit or facilitate a serious violation of international humanitarian law.”

However UKLFI argued that the decision by the government was made on grounds “which had nothing to do with whether the banned items might be used to violate international humanitarian law.”

According to UKLFI, statements from the government suggest it made a decision based on an assumption that “Israel could have done more to ensure that humanitarian assistance reaches the Gaza population and that there were credible allegations of mistreatment of Palestinian detainees, who were denied access by the Red Cross.”

UKLFI said: “Even if these alleged risks exist, they are not connected with the particular arms whose export licences are being suspended. Therefore the decision is not justified under criterion 2c of the SELC.”

UKLFI said: “The government’s statements also ruled out justification based on the conduct of the hostilities, in which the arms would be used.”

According to UKLFI the government had admitted “it has not been possible to reach a determinative judgment on the allegations regarding Israel’s conduct of hostilities.”

The group of lawyers also criticised emails it says were sent by the Solicitor-General, Sarah Sackman MP, responding to the concerns of some of her constituents.

According to UKLFI, Sackman told constituents “the UK government can only grant export licences for arms if it is confident that those arms will not be used in breach of international humanitarian law.”

However UKLFI claimed the Solicitor-General's emails were inaccurate and mis-stated the legal test.

The group said: “Under Sackman's test, any country trading with the UK would be treated as guilty of war crimes until proven innocent.

“If she was right then the entire UK defence industry would find it impossible to make any exports.”

In their letter to government the group argued: “This reverses the burden of proof in criterion 2c: as stated above, licences can only be refused under this provision if ‘the government determines that there is a clear risk that the arms might be used to commit or facilitate a serious violation of international humanitarian law’.”

UKLFI has requested a response by September 20.