Israel’s parliament approved a second piece of legislation on Monday to cut ties with the main UN provider of aid to Gaza and to designate it a terror organisation, threatening the agency as the humanitarian crisis in Gaza mounts.

The Bill prohibits ties between Israeli officials and UNRWA, the UN agency for Palestinian refugees, and strips its staff of their legal immunities.

It followed an earlier Bill passed banning all activity of UNRWA on Israeli soil.

The legislation, which would not take effect immediately, risks collapsing the already fragile aid distribution process at a moment when the humanitarian crisis in Gaza is worsening and Israel is under increased US pressure to ramp up aid.

The first vote passed 92-10 and followed a fiery debate between supporters of the law and its opponents, mostly members of Arab parliamentary parties.

Taken together, these Bills signal a new low in relations between Israel and UNRWA, which Israel accuses of maintaining close ties with Hamas militants.

The changes are also a serious blow to the agency and to Palestinians in Gaza who have become reliant upon it for aid throughout more than a year of war.

The Bills risk severely affecting the flow of humanitarian aid into Gaza.

More than 1.9 million Palestinians are displaced from their homes and Gaza faces widespread shortages of food, water and medicine.

International aid groups and a handful of Israel’s western allies, including the US, have voiced strong opposition.

US state department spokesman Matthew Miller, speaking to reporters in Washington, said the administration was “deeply concerned” by the legislation.

“There’s nobody that can replace them right now in the middle of the crisis,” he said.

UNRWA provides education, health care and other basic services to millions of Palestinian refugees across the region, including in the Israeli-occupied West Bank.

The Bills would come into effect 60 to 90 days after Israel’s foreign ministry notifies the UN, according to the spokesman for politician Dan Illouz, one of the co-sponsors of one of the Bills.

“UNRWA is the largest humanitarian organisation in Gaza. Who can do its job?” said Juliette Touma, communications director for the agency.