Egypt's Islamist-dominated constituent assembly has approved a draft constitution, as the judiciary threatens to dissolve it amid a power struggle with President Mohammed Morsi.The draft will now be sent to Mr Morsi, who is expected to call a referendum.The Supreme Constitutional Court is due to rule on Sunday on whether the assembly should be dissolved.Senior judges have been in a stand-off with the president since he granted himself sweeping new powers.An emergency decree issued last week said Mr Morsi's decisions could not be revoked by any authority, including the judiciary, until the new constitution had been ratified and a fresh parliamentary election is held.It also stated that the courts could not dissolve the constituent assembly.The president insists the powers he has taken are meant to be temporary and will protect the transition to a constitutional democracy, but their breadth has raised fears that he might become a new strongman and triggered mass opposition protests across the country. 'A difficult birth' The process of drafting a new constitution - to replace the one suspended after Hosni Mubarak was overthrown - began in March, but was slowed by a court ruling in April dissolving the first constituent assembly, amid accusations that it was dominated by Islamists.In June, political parties agreed on the make-up of a new panel, which included a range of politicians, members of the armed forces, police, judiciary and trade unions, as well as Muslim and Christian leaders.However, liberals, secularists and Coptic Christians continued to complain about the distribution of seats. Most of their representatives on the assembly boycotted its sessions over the past few months - leaving the majority Islamists with a relatively free hand - and 43 separate legal challenges to its constitutional legitimacy were filed.Mr Morsi's decree of 22 November gave the 100-member panel until January to complete the draft constitution. But after the Supreme Constitutional Court said it would soon rule on the lawsuits, supporters of the president on the assembly decided to pass a rushed draft to head off the threat of dissolution.