It should be a time of unalloyed joy for Tim Brown. The director of one of Britain's most well-regarded choirs is beginning a six-concert tour of Israel this week.

The choir of Clare College, Cambridge, will be singing Bach's Christmas Oratorio with the Israel Camerata Orchestra. But the singers have not, as a choir, been able to perform in East Jerusalem or Bethlehem in the occupied West Bank, after a Palestinian protest against the choir's tour of Israel.

The choir has been caught in the passionate arguments over whether Israel should be boycotted.

Tim Brown says he is very disappointed. He had been hoping that the choir could precede its tour of Israel with a visit to St George's Cathedral in East Jerusalem, and the Church of the Nativity in Bethlehem. They had been invited to sing in both locations by the Anglican Bishop of Jerusalem.

But that was before the London-based Palestine Solidarity Campaign swung into action. The campaign wrote a letter, signed by more than 200 people, asking that the choir cancel its tour of Israel or risk, in their words, "appearing indifferent to Palestinian suffering".

The Palestinian Authority joined in.

According to one of those involved, the PA asked the Bishop of Jerusalem to withdraw the invitation for the choir to sing in East Jerusalem and Bethlehem.

The choir was informed that it would not be welcome in Bethlehem, should its members try to come in, en masse, as part of the bishop's pilgrimage.

The choir's director says his frustration is borne of what he describes as his own pro-Palestinian stance: he has taught and performed with Palestinian musicians. Mr Brown was very keen for his students to see the West Bank barrier and, as he put it, the "privations" caused by the Israeli occupation.

Betty Hunter, the general secretary of the Palestine Solidarity Campaign, says that desire to travel to the West Bank does not excuse the choir's tour of Israel. That tour, she says, is "surprising and shocking" - something which, in her words, "promotes Israel as a normal state rather than one which represses Palestinians".

The issue of whether Israel should be boycotted has gained publicity in recent months with campaigns led by British trades unions. Separately, some Israeli MPs reacted angrily to the British government issuing guidelines over the labelling of produce imported from Israeli settlements in the West Bank. British officials are keen to stress that their move has nothing to do with a boycott.

But Betty Hunter says that these are but the opening skirmishes of a whole new boycott campaign that she says will open up over the next few months.