The main defense lawyers of Australian journalist Peter Greste and another Al-Jazeera reporter being trial in Cairo quit Thursday, accusing the satellite news station which employs them of working against Egypt.

Greste, watching proceedings from the caged dock, appeared taken aback when his lawyers announced to the judge that they were dropping the case, which has sparked international concern for the detained reporters.

A jailed Al-Jazeera journalist who has been on hunger strike for over 100 days said he holds the Egyptian authorities responsible if his health fails, according to a video aired on Wednesday.

Abdullah Elshamy was arrested on August 14 when police broke up a sit-in of supporters of ousted Islamist president Mohamed Morsi in Cairo, which led to clashes that killed hundreds.

An Egyptian court Wednesday sentenced 79 supporters of ousted president Mohammed Morsi to jail terms of between five and 10 years over their involvement in deadly clashes, judicial sources said.

The defendants were convicted for participating in clashes between Morsi supporters and opponents that killed 12 people in the Mediterranean city of Alexandria last July, after the military overthrew the Islamist president, the sources said.

A dissident movement which spearheaded president Hosni Mubarak's overthrow in 2011 announced Wednesday a boycott of Egypt's presidential poll that it said would only serve to "enthrone" ex-army chief Abdel Fattah al-Sisi.

The April 6 movement was banned last month and its leader has been jailed, amid a crackdown by the military-installed regime on the opposition following the overthrow of Islamist president Mohammed Morsi in July.

An al-Jazeera journalist held in Egypt since August is in "critical" health and could slip into a coma after more than 100 days on hunger strike, his brother said Tuesday.

Abdullah Elshamy was arrested on August 14 when police dispersed supporters of ousted Islamist President Mohammed Morsi in Cairo, killing hundreds in clashes.

Egypt's presidential frontrunner Abdel Fattah al-Sisi sought to ease concerns Monday that he would restrict freedoms, insisting that democratic principles and human rights were guaranteed under the new constitution.

Sisi, who is expected to easily win the May 26-27 election, said last week that democratic aspirations expressed in mass protests since 2011 were affecting national security and slowing a much-needed economic recovery.

Egypt said Monday it has dismantled three "terrorist cells" targeting security forces, including one run by jihadists and another operated by student supporters of ousted Islamist president Mohammed Morsi.

Militants have stepped up attacks on security forces since the army overthrew Morsi in July last year.

Presidential frontrunner Abdel Fattah al-Sisi said on Sunday Egypt's situation will improve in two years, adding that he would not hesitate to resign if there were mass protests against him.

Sisi, lauded by millions of Egyptians for ousting Islamist president Mohamed Morsi in July last year, is expected to trounce his only rival, leftist leader Hamdeen Sabbahi, in the May 26-27 election.

An Egyptian court on Sunday sentenced 36 students of the prestigious Al-Azhar university to four years in prison each over violent protests backing ousted President Mohammed Morsi, judicial sources said.

Students supporting Morsi regularly hold demonstrations calling for his release at several Egyptian universities and in particular at Cairo's Al-Azhar university, a prestigious seat of Sunni Islamic learning.

Presidential frontrunner Abdel Fattah al-Sisi, who ousted elected leader Mohammed Morsi, has prioritized stability over freedoms, insisting it will take up to 25 years for Egypt to achieve "true democracy".

Three years after millions of protesters demanding "bread, freedom and social justice" ousted strongman Hosni Mubarak's regime, Sisi warned such aspirations were hindering national security and slowing a much-needed economic recovery.