In an unprecedented criticism of the Israeli siege of Gaza, a senior official in the Médecins Sans Frontières (MSF) humanitarian charity has described his organisation’s work among the 1.8 million besieged Palestinian refugees as akin to being “in an open-air prison to patch up prisoners in between their torture sessions”.

Jonathan Whittall, head of humanitarian analysis at MSF, who worked in Libya during the 2011 war, in Bahrain during the uprising of the same year, in Syria, Afghanistan, Pakistan, South Sudan and Darfur, has bluntly asked his colleagues: “At what point does MSF’s repeated medical action in an unacceptable situation [like Gaza] become complicity with aggression and oppression?”

Unlike other medical charities, MSF has always encouraged its staff to speak frankly about the dangers and moral problems they face, and the long and passionate report from Mr Whittall – unlike those of other humanitarian groups, which prefer to silence their staff – is in keeping with MSF’s rules. But its accusations against Israel are sure to arouse fierce Israeli condemnation during a disproportionate war – supposedly fought to prevent Hamas rocket attacks on Israel – in which the Israeli military has killed well over 200 civilians, many of them women and children.

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“An entire population is trapped in what is essentially an open-air prison,” Mr Whittall writes. “They can’t leave and only the most limited supplies – essential for basic survival – are allowed to enter. The population of the prison have elected representatives and organised social services.

“Some of the prisoners have organised into armed groups and resist their indefinite detention by firing rockets over the prison wall. However, the prison guards are the ones who have the capacity to launch large-scale and highly destructive attacks on the open-air prison.”

In a comparison which is also certain to infuriate Israel, Mr Whittall, who is based in Beirut, says that the limitations of humanitarian groups in Gaza are not unique. “In 2012,” he writes, “MSF closed its projects in the prisons of Misrata, Libya. Our doctors were outraged to be in a position where we were providing treatment to patients who were being tortured by state authorities. At the time, MSF spoke out strongly: ‘Our role is to provide medical care to war casualties and sick detainees, not repeatedly to treat the same patients between torture sessions’.”

Shape Created with Sketch. In pictures: Israel-Palestinian demonstrations around the world Show all 18 left Created with Sketch. right Created with Sketch. Shape Created with Sketch. In pictures: Israel-Palestinian demonstrations around the world 1/18 London Palestine's supporters and Palestinians themselves gathered in Portland Place outside the BBC headquarters, to protest against the alleged lack of information in British news on the war in Palestine 2/18 London Palestinian and pro-Palestinian demonstrators assemble outside the BBC TV Centre in central London to protest against it's biased, pro-Israeli reporting of the conflict in Gaza 3/18 London Pro-Palestinian protesters stand on a London bus during a demonstration outside the Israeli embassy on 11 July Getty Images 4/18 London A protester holds a placard during the protest on 11 July Getty Images 5/18 London Demonstrators scale a London bus during the protest on 11 July Getty Images 6/18 London Police line the demonstration outside the Israeli embassy on 11 July Getty Images 7/18 Washington, US A man waves a flag at a protest outside the Israeli Embassy in Washington DC on on 11 July Getty 8/18 Mexico City A rally against the Israeli military held outside the Mexican Foreign Ministry building in Mexico City on 11 July Getty 9/18 Tunisia Tunisians hold Palestinian flags as they protest in Habib Bourguiba Avenue in Tunis on 11 July Getty 10/18 Jakarta, Indonesia A portrait of Israel Prime Minister Benjamin Netanyahu is sprayed with fake blood at a rally in Jakarta on 11 July Getty 11/18 Jakarta, Indonesia A pro-Palestinian rally in Jakarta on 11 July Getty 12/18 Rome, Italy A rally in downtown Rome on 11 July Getty 13/18 Paris, France Pro-Palestinian protesters in Paris on 11 July Getty Images 14/18 New York, US Pro-Israeli protesters rally near the Israeli Mission to the United Nations on 9 July Getty 15/18 New York, US The pro-Israeli protest on 9 July Getty 16/18 New York, US A man shouts "Free Palestine" during a march in midtown Manhattan on 9 July Reuters 17/18 New York, US A march in Manhattan demanding an end to the escalating Israeli-Palestinian hostilities on 9 July Reuters 18/18 New York, US Protesters rally across the street from the Israeli Mission to the United Nations in New York on 9 July 9 Getty Images 1/18 London Palestine's supporters and Palestinians themselves gathered in Portland Place outside the BBC headquarters, to protest against the alleged lack of information in British news on the war in Palestine 2/18 London Palestinian and pro-Palestinian demonstrators assemble outside the BBC TV Centre in central London to protest against it's biased, pro-Israeli reporting of the conflict in Gaza 3/18 London Pro-Palestinian protesters stand on a London bus during a demonstration outside the Israeli embassy on 11 July Getty Images 4/18 London A protester holds a placard during the protest on 11 July Getty Images 5/18 London Demonstrators scale a London bus during the protest on 11 July Getty Images 6/18 London Police line the demonstration outside the Israeli embassy on 11 July Getty Images 7/18 Washington, US A man waves a flag at a protest outside the Israeli Embassy in Washington DC on on 11 July Getty 8/18 Mexico City A rally against the Israeli military held outside the Mexican Foreign Ministry building in Mexico City on 11 July Getty 9/18 Tunisia Tunisians hold Palestinian flags as they protest in Habib Bourguiba Avenue in Tunis on 11 July Getty 10/18 Jakarta, Indonesia A portrait of Israel Prime Minister Benjamin Netanyahu is sprayed with fake blood at a rally in Jakarta on 11 July Getty 11/18 Jakarta, Indonesia A pro-Palestinian rally in Jakarta on 11 July Getty 12/18 Rome, Italy A rally in downtown Rome on 11 July Getty 13/18 Paris, France Pro-Palestinian protesters in Paris on 11 July Getty Images 14/18 New York, US Pro-Israeli protesters rally near the Israeli Mission to the United Nations on 9 July Getty 15/18 New York, US The pro-Israeli protest on 9 July Getty 16/18 New York, US A man shouts "Free Palestine" during a march in midtown Manhattan on 9 July Reuters 17/18 New York, US A march in Manhattan demanding an end to the escalating Israeli-Palestinian hostilities on 9 July Reuters 18/18 New York, US Protesters rally across the street from the Israeli Mission to the United Nations in New York on 9 July 9 Getty Images

Since 2010, MSF has run a post-operation clinic in Gaza City, where 80 per cent of the patients suffer from severe burns, and provides specialised hand surgery in the Nasser hospital at Khan Younis, and intensive care training to medical and paramedical personnel at both the Nasser and Shifa hospitals.

During conflict, Mr Whittall adds, “the voice of outrage of MSF medical teams is drowned out by the propaganda war that erupts each time a [military] operation such as this takes place and by the concerns that too loud a voice of criticism could cut off the organisation’s surgical teams from being able to reach the Gaza Strip.” Although Mr Whittall does not say so, the same constraints were felt by humanitarian groups when confronted by civilian populations in desperate need of help in the Syrian war.

In another sideswipe at the Israeli military’s actions against Gaza, Mr Whittall remarks that “everyone pays the price for living under siege and for their acts of resistance. Medical workers have been killed and health structures damaged. In such a densely populated environment, the claims of not targeting civilians in air raids are of little comfort. There are always limits to humanitarian action. Humanitarian organisations can treat the wounded. But we can’t open borders to end violence.”

The MSF official also notes that while confronting the “limits of humanitarianism” is a daily reality for MSF field workers, “it is made only more apparent by the duration of the suffering and the international political configuration that allows for the sick political statements and endless violence to continue.” Mr Whittall says that as “the open-air prison of Gaza braces for more air raids and a possible ground operation,” the limits of MSF’s work remain obvious, and he demands that Palestinians should be allowed “to move freely and to seek safety in times of violence, including into Egypt… Civilians and civilian infrastructure – including medical workers, health centres and ambulances – should never be targeted. Humanitarian aid and its workers should be given unhindered access at all times – not as a favour but as a legal responsibility.”

Mr Whittall’s analysis will evoke much sympathy among other humanitarian organisations, and with EU officials who find that their assistance in the Palestinian occupied territories or Gaza is taken for granted – or even abused – by the Israelis. EU humanitarian projects, both in Gaza and the West Bank, have been destroyed by the Israeli army – with afterwards scarcely a breath of criticism from the EU itself, which has no connection with MSF.