[JURIST] Egypt's four largest opposition parties – the Tagammu, Karama, Wafd and Nasserist parties [party websites] – announced Thursday they will boycott next week's referendum on controversial constitutional amendments [JURIST report] proposed last year by President Hosni Mubarak [official profile; JURIST news archive] and recently approved by lawmakers [JURIST report]. The announcement comes one day after Egyptian opposition group the Muslim Brotherhood [party website, JURIST news archive] announced it too planned to boycott the referendum [JURIST report], which was originally scheduled for April 4 but then rescheduled for next Monday. Opponents have called the expedited timeframe an attempt to quash opposition to the amendments. AFP has more.

Critics say President Mubarak is using the amendments to clear the way for his son to assume the presidency when he steps down. The constitutional changes will prohibit religious political parties and require that any future presidential candidates be from a party holding at least 3 percent of parliamentary seats. They also would allow the president to refer terrorist crimes to a "judicial authority," which critics interpret as allowing the president to use military courts which render unappealable decisions. Rights group Amnesty International [advocacy website] specifically condemned the anti-terrorism law [press release], calling the amendments the "greatest erosion of human rights in 26 years."

Also on Thursday, prominent Egyptian judge Mahmoud Mekky said he feared fraud could mar the referendum's credibility. He called for international human rights groups to monitor them, even though a small panel of judges has volunteered to watch for potential abuses. Mekky said there were not enough volunteers to replace international oversight. The vote requires only a simple majority to pass. Reuters has more.