Sir – Hugo Slim (Letters, September 19) claims our advertisement transposing an army checkpoint and the Israeli security wall on to St Aldates in Oxford is misleading and facile and would only make sense if Oxford were at the heart of a protracted conflict.

It is difficult to understand the situation in Israel and the occupied Palestinian territory if you have never been there. That is why we chose to use the transposed image of the wall to draw attention to one aspect of the reality.

Of course, there would not be walls like this and soldiers on the street without some cause. But that does not justify all the measures Israel takes in the name of security.

The separation wall, numerous checkpoints and barriers and the permit regime are an intolerable impediment to the well-being of Palestinian civilians who have been living under occupation for 46 years — people who have as much of a right to health as someone living in Oxford or anywhere else for that matter.

The main Palestinian specialised hospitals are, and always have been, based in East Jerusalem which has been illegally annexed by Israel. Most of the complex medical cases from West Bank and Gaza are referred to these hospitals. Palestinians have the right to go to them — just as Oxford patients have the right to go to the Radcliffe.

Whichever way you look at it, one in five people being denied travel permits to get to these and other hospitals in east Jerusalem is far from a positive statistic. While Israel has the right to protect its citizens, it also has a duty under international law to ensure the health and well-being of the Palestinian civilian population and must allow for the free flow of people, services and goods.

Tony Laurance, Chief executive officer, Medical Aid for Palestinians