The agency’s fleet of 276 lorries, buses and cars is stranded, leaving UN staff unable to distribute aid to 735,000 refugees, while health and social services workers are already unable to visit refugee camps.

The border closures have caused flour mills in the Palestinian coastal strip to close, bakeries to ration bread and pharmacies to run short of drugs.

As the new Hamas Cabinet-in-waiting arrived at the Palestinian parliament for the first time yesterday, wearing pinstripe suits and carrying briefcases, the Interior Minister spoke of a fresh intifada were the blockade not lifted. “If the Israelis continue with the closures they have to live with the consequences when it comes to the point that our people find they have nothing to lose,” Said Siyam said. “The Israelis will pay the price for their anger, and there will be a new intifada of the Palestinian people.”

John Ging, Gaza director of operations for the UN Relief and Works Agency, appealed for an immediate resolution of the crisis, which has led to increasing shortages of basic foods.

Israel cites security reasons for keeping the main border crossing at Karni closed for more than 45 days this year. Palestinians believe that the crossing is being kept closed to punish them for electing Hamas, the militant Islamic group, to run the Palestinian Authority.

Israel did open the Karni crossing yesterday to allow wheat into Gaza, but Mr Ging protested that the limited move was completely inadequate. “We have shortages of all the essential commodities and . . . 10 per cent of capacity is not going to meet the need,” he said.

Officials said that the UN had 60,000 litres of fuel waiting to be brought in through the Karni crossing.

“The politics of this situation is not relevant to us. What is relevant is the humanitarian impact on the street,” Mr Ging complained. “We flagged this up to the Israelis two months ago and we were assured and reassured that a solution would be found before we ran out. Now we have run out.”

Israel insisted that it was forced to close Karni because of intelligence warnings that Palestinian militants plan to attack the crossing. “Within the constraints of the difficult situation at Karni we have made the maximum effort to open it for two days in a row,” said Mark Regev, an Israeli government spokesman.

Israel has offered the alternative of a new, smaller crossing at Kerem Shalom. The Palestinians refuse to countenance an Israeli-controlled lifeline to the outside world. “We understand that Kerem Shalom cannot take the volume of Karni but we really don’t understand why the Palestinians fail to accept it as a temporary solution,” Mr Regev said.

Israel, the US and the EU say that Hamas is a terrorist organisation, but it has urged the international community to accept that it won free elections. Hamas has refused demands to recognise Israel, renounce violence and abide by past agreements.

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