I met Karen AbuZayd, the head of UNRWA, when she was sitting in the basement dining room of a trendy London hotel beside a mirror on which an artist has written in gold letters: "this is shit."It is understandable that Mrs AbuZayd, whose UN agency looks after the welfare of Palestinian refugees, did not wish to be photographed in front of the art work. But the message on the mirror aptly sums up the dramatic humanitarian situation in the Gaza Strip, as she was the first to point out.

The Israeli blockade has caused an ever worsening crisis for the 1.5m Palestinians in Gaza since it was imposed after the election of Hamas in January 2006. Israel has refused to lift the blockade for as long as the Palestinian militants’ rockets come over the fence.

With the press barred from crossing into Gaza for the past month, Mrs AbuZayd brought me up to date with the current misery and hardship for the Palestinian population trapped inside.

Ninety five percent of the private sector has collapsed since June. Of the 1.1m registered Palestinian refugees in Gaza, 800,000 need food distribution. Electricity supplies are on for eight hours a day. 120,000 people have not had water for a week. They are cooking with wood in high rise apartments, which is an obvious fire risk.

UNRWA has not built any houses for the growing refugee population because sand and gravel cannot be brought into the territory. Children are going to school in shifts because of the lack of teachers. Some are falling asleep at their desks because there isn’t enough food at home, so the UN has introduced a feeding programme for them at school. When they go home, they have to study by candlelight.

Mrs AbuZayd has now run out of superlatives for describing how bad things are. She has been based in Gaza for the last eight years, and has therefore been there through kidnappings and the violent eviction of Fatah by Hamas.

On the humanitarian front, she says that every time you think the situation can’t get any worse, it does. She pointed at the mirror, before concluding: "it’s grim."