Sixteen charities, including Oxfam and Amnesty International, have criticised the international community for not doing enough to end the Gaza blockade in a report published a year on from Operation Cast Lead.

The report, Failing Gaza, published this week, claims there has been a “failure” of the international community to do all it can to lift the blockade and calls for “concerted action”.

It says that the Middle East Quartet should “abandon the failed policy of non-engagement and begin political dialogue with all Palestinian parties” as well as “recognise any representative national authority”.

It also urges the international community to press Israel to provide compensation for damage caused by Operation Cast Lead and other Israeli military action and support investigations into violations of human rights.

The charities’ report was echoed by Lib Dem leader Nick Clegg, who insisted: “The blockade must end.”

But Robin Shepherd, director of international affairs at the think-tank, the Henry Jackson Society, has called for a boycott of the charities which authored the report, which he called “appalling”.

He wrote on his blog: “It shows almost total contempt for basic standards of balance and contextualised analysis. It is wilfully ignorant. It is peppered with hyperbole. It is, in short, a travesty of what recognised charitable institutions should be about.”