Israeli authorities have threatened four Palestinian politicians with expulsion from Jerusalem because of their affiliation to Hamas in a case which could have wide ramifications for others deemed undesirable by the Jewish state.

Mohammed Abu Tir, 59, a member of the Palestinian Legislative Council (PLC), is in police custody for failing to leave the city by the end of last month. Instantly recognisable for his dyed orange beard, Abu Tir was released from an Israeli prison in May after almost four years, and was immediately told he must abandon political activity or leave Jerusalem.

Two other members of the PLC and a former Palestinian minister have moved into the grounds of the International Red Cross and Red Crescent in East Jerusalem in protest at the deportation orders.

The men's cases are to be heard by the supreme court in September. However the court rejected a plea to prohibit deportation in the interim, so the men are at risk of being expelled from the city at any time.

The threatened deportations are part of a wider pattern of revoking the Jerusalem residency permits of Palestinians from the city. In most cases, Israel claims that the people it strips of the right to live in Jerusalem have voluntarily relocated to the West Bank or abroad. This is often contested by the individuals concerned and human rights groups representing them.

In 2008, more than 4,500 Palestinians were excluded from Jerusalem.

However the case of the four Hamas politicians is the first time Israel has cited political grounds for expelling people from the city.

"For the first time Israel is using a claim of disloyalty to revoke residency," said Hasan Jabarin, director of the Israeli human rights group Adalah. "The consequences for Palestinians in East Jerusalem are dangerous. This case could open a new window to revoking residency on purely political grounds."

Abu Tir was imprisoned with dozens of Hamas politicians and activists after the Palestinian election in January 2006, which was won by the Islamic militant party.

"The election was legal and transparent. They found themselves in jail simply because they were elected," said Jabarin.

The men's case has been raised in the past week in both the House of Commons and the House of Lords. Labour MP Andrew Slaughter asked whether the British government had raised the issue with the Israeli government.

Mahmoud Abbas, the Palestinian president, urged Israel to "stop these sort of actions". Ahmad Bahar, the deputy speaker of the Palestinian parliament, described the revocation of residency permits as a "massive ethnic cleansing campaign".

More than 270,000 Palestinians live in East Jerusalem, which Israel occupied and annexed in 1967.

In a separate development, Israel's supreme court has rejected a petition on behalf of Gazan lawyer Fatima Sharif to be allowed to travel to the West Bank to begin a masters degree in human rights, citing the "current political-security situation".

The Israel Defence Forces made it clear in the court hearing yesterday that there would be no relaxation of the policy restricting the movement of Palestinians in and out of Gaza except in the most extreme circumstances, despite Israel's decision to ease its blockade of the territory.