Sir Keir Starmer said he is “really appalled” by Israel’s decision to block aid from entering Gaza, as the Prime Minister was pressed on whether a “genocide” is being committed against Palestinian people.

Israel announced it had cut off Gaza’s electricity supply on Sunday evening, a week after it suspended delivery of humanitarian supplies to the territory.

The decision has sparked concern about the impact on drinking water in Gaza, with a key desalination plant now reliant on generators to produce significantly less water than previously.

At Prime Minister’s Questions, Independent MP Zarah Sultana said Israel’s decision is “further evidence of genocide”.

Independent MP Zarah Sultana spoke about the aid situation in Gaza (Yui Mok/PA)

Sir Keir told the Commons the blocking of aid into Gaza risks breaching international law and the Government is “doing everything we can to alleviate that situation”.

Ms Sultana lost the Labour whip in July last year after she rebelled against the Government in a vote on the two-child benefit cap.

On Wednesday, the MP for Coventry South said: “In October 2023, in an interview with LBC, the Prime Minister said, and I quote, ‘I think Israel does have that right’, when asked if cutting off power and water to Gaza was appropriate.

“For 11 days now, Israel has blocked the entry of vital goods and aid into Gaza, subjecting over two million people to collective punishment and starvation.

“Israel’s decision to also cut off electricity to a water plant supplying drinking water to half a million people is yet another blatant violation of international law and further evidence of genocide against the Palestinian people.

“In light of these facts, does the Prime Minister still maintain that Israel is not committing genocide?”

Children carry water in plastic jerrycans at a tent camp for displaced Palestinians in the Zeitoun neighbourhood of Gaza City (Jehad Alshrafi/AP)

Sir Keir replied: “I’m really appalled by Israel blocking aid when it is needed at greater volume and speed than it’s ever been needed.

“Blocking goods and supplies and power entering Gaza risks breaching international humanitarian law, and it shouldn’t be happening, and we are doing everything we can to alleviate that situation.”

On Monday, Downing Street said it was “deeply concerned” by reports that Israel had cut off Gaza’s electricity and urged Tel Aviv to reverse its decision.

The Prime Minister’s official spokesman said: “Our position is humanitarian aid should never be contingent on a ceasefire or used as a political tool.”