What's the referendum about?

The Egyptian government wants to make changes to the country's constitution, especially those sections concerning the conduct of elections and anti-terror legislation.

What changes are being proposed?

The proposed amendments include changes to 34 articles of the constitution. The changes include a ban on the establishment of religious parties and allow for the adoption of a new election law. They would allow the president to dissolve parliament unilaterally and dispense with the need for judicial supervision of every ballot box.

They would also allow for a new anti-terrorism law to replace emergency legislation that has been in place since 1981, when Hosni Mubarak first became president after the assassination of his predecessor, Anwar al-Sadat. The new law enshrines sweeping police powers of surveillance and arrest and allows for civilians to be tried by military courts in terrorism cases.

Why is the government so keen on the changes?

The government says that the proposed changes to the constitution are long overdue reforms that will strengthen democracy and the rule of law.

Why is the opposition boycotting the referendum?

The opposition says that the aim of the changes is to strengthen President Mubarak's grasp on power. It maintains that the watering down of the judicial supervision of elections will increase the likelihood of election abuses.

Parties such as the Muslim Brotherhood are likely to be hit hard by the proposed ban on political activity based on religion.

The opposition is also unhappy about the proposed new anti-terrorism law, which it says will turn Egypt into a police state.

It also objects to the bringing forward of the date of the referendum - which was originally set for 4 April - saying that this is indicative of the government's determination to ram through changes without taking into account any opposition.

What does the rest of the world say?

The human rights group Amnesty International is highly critical of the proposals, saying that they amount to the greatest erosion of human rights in Egypt since emergency laws were enacted in 1981 in the wake of the assassination of President Sadat.

The US has also expressed muted criticism of the proposed constitutional amendments.