Britain has criticised Israel for extending the sentence of a Palestinian man in prison for his role in weekly and often violent anti-Israel protests.

Abdallah Abu Rahma, a leading figure in the regular demonstrations in the West Bank village of Bilin, was handed the 12 month sentence in October 2010 for incitement and for organising and participating in the unauthorised protests.

He had been arrested eight months earlier, so has now served the conditions of his initial sentence.

His sentence was extended to 16 months after the military prosecution argued that there was a risk he would resume his "illegal activities" if he was freed. Such an extension can only be granted by the Israeli courts in special circumstances.

The organisers claim the Bilin protests are intended to oppose the path of the West Bank security fence, which Israel’s Supreme Court has ordered the government to reroute.

But described by the organisers as non-violent, on a number of occasions the protests have ended in Palestinians throwing rocks at Israeli soldiers.

A spokesperson from the Foreign and Commonwealth Office said: “We remain concerned that his extended sentence is intended to prevent Abdallah and other Palestinians from exercising their right to non-violent protest”.