The SNP leader told the Prime Minister: “The civilian death toll is intolerable, as is the killing of humanitarian workers who deliver vital aid to Palestinians facing starvation and violence at the hands of this Israeli government.

“By not stopping arms sales to Israel, the UK is in danger of being complicit in the killing of innocent civilians.”

The SNP is already calling for MPs to return to the House of Commons early from their Easter break to “debate and vote on ending arms sales to Israel”.

READ MORE: Humza Yousaf marks first anniversary as First Minister

Stephen Flynn, the SNP’s Westminster leader, said that “if the UK Government are unwilling to act then Parliament should force them to do so”.

Meanwhile Mr Yousaf, whose parents-in-law were trapped in Gaza for several weeks last year after the conflict erupted, said that “Israel’s actions have long since gone beyond a legitimate response.”

In his letter to Mr Sunak, the First Minister said: “The UK Government continue to allow British-based companies to arm Israel despite the fact that Israel has killed children, women, aid workers and bombed hospitals, schools and refugee camps.”

The Prime Minister however has defended the UK’s “careful export licensing regime”.

Speaking to the Sun newspaper’s Never Mind the Ballots show, Mr Sunak said: “I think we’ve always had a very careful export licensing regime that we adhere to.

“There are a set of rules, regulations and procedures that we’ll always follow.”

Mr Sunak said he had been “consistently clear” to Israeli Prime Minister Benjamin Netanyahu since the start of the conflict that while the UK would “defend Israel’s right to defend itself and its people against attacks from Hamas, they have to do that in accordance with international humanitarian law, protect civilian lives”.

He stressed the importance of getting more aid into Gaza, saying: “That’s what we’ve consistently called for and what we want to see actually is an immediate humanitarian pause to allow more aid in, and crucially the hostages to be released, and that’s what we’ll continue to push for.”