A British diplomat has resigned from the Foreign Office as he believes the department "may be complicit in war crimes" for continuing to allow arms sales to Israel.
Mark Smith, listed as a second secretary in the British embassy in Ireland, wrote in a resignation letter to colleagues that was posted online that members of the Israeli government and military have expressed "open genocidal intent".
Smith also said that it was "deeply troubling" that the department had "disregarded" his concerns on the illegality of continued arms sales.
In a letter to colleagues, he wrote: "It is with sadness that I resign after a long career in the diplomatic service, however I can no longer carry out my duties in the knowledge that this department may be complicit in war crimes."
Smith said he is a former penholder on the arms export licensing assessment in the Middle East and North African Department, experience he said makes him a "subject matter expert" on arms sales policy.
"Each day we witness clear and unquestionable examples of war crimes and breaches of international humanitarian law in Gaza perpetuated by the state of Israel," he said.
"Senior members of the Israeli government and military have expressed open genocidal intent, Israeli soldiers take videos deliberately burning, destroying and looting civilian property and openly admit to the rape and torture of prisoners."
He said there is no justification for the UK's continued arms sales to Israel and said he had raised this at every level in the organisation including through an official whistle blowing investigation.
He received nothing more than "thank you we have noted your concern".
"Ministers claim the UK has one of the most 'robust and transparent' arms export licensing regimes in the world, however this is the opposite of the truth," Smith said.
He concluded the letter: "I hope that we can look back on history and be proud."
While in opposition the now Foreign Secretary David Lammy urged the Foreign Office (FCDO) to publish its formal legal advice as to whether Israel was complying with international humanitarian law.
An FCDO spokesperson said: "This government is committed to upholding international law.
"We have made clear that we will not export items if they might be used to commit or facilitate a serious violation of international humanitarian law.
"There is an ongoing review process to assess whether Israel is complying with international humanitarian law, which the Foreign Secretary initiated on day one in office.
"We will provide an update as soon as that review process has been completed."
Since 2008, the UK has licensed arms worth more than £576 million ($A1.1 billion) to Israel, according to analysis of government export data by the Campaign Against Arms Trade.
In June this year, the government published data on licences granted to Israel since the Hamas attack on Israel on October 7, which showed it had issued 42 licences between October 7, 2023 and May 31 2024.
This week, the US and fellow mediators Egypt and Qatar said they were closing in on a ceasefire deal after two days of talks in Doha, with American and Israeli officials expressing cautious optimism, despite Hamas showing resistance to what it called new demands by Israel.
Lammy visited Israel last week alongside French foreign minister Stephane Sejourne, releasing a joint statement on Sunday in which they expressed a "commitment to working ever more closely together in a new spirit of co-operation".
"Our visit to a Palestine Red Crescent Society warehouse was a stark reminder of the toll of this conflict, which is unacceptable," the statement said.
The war has killed more than 40,000 Palestinians, according to local health authorities, displaced the vast majority of the territory's 2.3 million residents and led experts to warn of famine and the outbreak of diseases such as polio.
