The move followed a joint announcement between the UK, France and Canada, promising “concrete actions" if Israel does not stop its renewed military operations in Gaza and fails to lift restrictions on aid entering the Strip.
"Right now, children in Gaza are starving while food and medicine sit just minutes away, blocked at the border,” the open letter, also signed by director Danny Boyle and Irish actress Nicola Coughlan, said.
"Words won’t feed Palestinian children – we need action.”
It went on: “Every single one of Gaza’s 2.1 million people is at risk of starvation, as you read this. Mothers, fathers, babies, grandparents – an entire people left to starve before the world’s eyes.”
Israel has denied that there is a famine or risk of widespread starvation in Gaza.
However, on May 18, Jerusalem said it would allow a "basic amount of food" to enter Gaza to make sure "no starvation crisis develops" after blockading the territory since 1 March.
The UK has already partially suspended arms sales to Israel on the basis that the Foreign Office assessed there was a risk of weapons being used in violation of international law.
It has not, though, suspended its participation in the F-35 fighter jet programme as it does not sell the planes directly to Israel. Instead, some of the aircrafts’ components are manufactured in British factories and then released to the US-led scheme to build the final product, some of which are sold to Israel.