Egypt’s constitution will be amended to allow President Abdel Fattah el-Sisi to remain in office until 2030 after the government claimed to have won 89 per cent support in a much-criticised referendum.

The Egyptian electoral commission said 11 per cent of citizens voted against the constitutional amendments, which also tighten Mr Sisi’s grip on the judiciary and expand the military’s role in Egyptian politics.

Amnesty International condemned the referendum as a sham, saying the lack of debate over the major constitutional changes showed “the Egyptian government's contempt for the rights of all people in Egypt”.

Mr Sisi’s supporters hailed the changes as necessary to allow the president to stay in office so he could continue economic reforms and crush a jihadist insurgency in the Sinai desert.

Government supporters honked car horns in central Cairo and blared celebratory music after the result was announced.

The constitutional changes are the latest step in Mr Sisi’s consolidation of power since he toppled Egypt’s elected Islamist president in a 2013 military coup and seized control of the state.