The Hamas de facto government is one of the only employers in Gaza with a growing payroll, after a record slump resulting from the Israeli blockade imposed when the Islamic faction took control a year ago.

This emerges from a new UN report showing that more than an unprecedented 52 per cent of Gaza households have now plunged below the internationally-designated poverty line despite continued humanitarian assistance, while unemployment has reached 45 per cent for the first time.

The report, from the UN Relief and Works Agency (UNRWA), contrasts the more than half of households in Gaza living in poverty with the 19 per cent living in poverty in the West Bank, thanks to the lifting of the Israeli and international embargo on the Ramallah-based Palestinian Authority last summer. Poverty means a family of six spending below £66 per week.

It also points out that the record unemployment rate compares with 29 per cent in the occupied Palestinian territories as a whole – itself one of the highest jobless levels in the world. The closure of the crossings to commercial goods has shut down 95 per cent of Gaza's private-sector industry.

There was a 2.2 per cent increase in jobs between 2006 and 2007, including in unpaid work by family members, and jobs provided by the Hamas-controlled institutions. While not highlighted in the report, the third main category of job growth is thought to be the dangerous digging and smuggling through hundreds of illicit tunnels between Egypt and Gaza.

The public-sector category – which the report says accounted for roughly 25 per cent of the modest job growth of about 4,000 between 2006 and 2007 – is believed to include work on Hamas-run job-creation schemes, in administration and in the faction's security services.

The report, based on data from the Palestinian Central Bureau of Statistics, reinforces anecdotal evidence given by such people as one prominent Gaza construction employer who recently estimated that of more than 100 workers he was obliged to lay off because of a lack of materials, a majority had joined the Hamas police force or its military wing. Some diplomats have privately questioned the wisdom of a blockade which makes it easier for Hamas to recruit force members. The UN says that the burgeoning youth segment of the Palestinian labour force (15- to 24-year-olds) was "the ... most prone to increased unemployment".

Chris Gunness, a spokes-man for UNRWA, said: "If you deprive young people of an economic future, you deprive them of hope and when hope vanishes, what is left? How better to prevent despair and economic misery taking hold of a whole generation than to re-open Gaza's borders?"