File photo - A group of protesters shout slogans against Egypt's President Mohammed Morsi during a demonstration in front of the White House in Washington.

Opposition groups have spurned an offer from the Egyptian President Mohamed Morsi to reverse the highly controversial power grab he issued in November, vowing to escalate their protests until he scraps a planned referendum on the new constitution.

With no end in sight to the country's simmering political tensions, thousands of protesters were due to stage another march on Mr Morsi's presidential palace on Sunday night to hammer home their demands.

Mr Morsi met with various political figures on Saturday. The talks were hamstrung from the outset after a boycott by all of the major opposition parties. Most of those who turned up were Islamists or allies of the President.

But following a 10-hour discussion - and a military statement warning of “disastrous” consequences to the current stand-off - the President agreed to ditch a decree issued in November in which he granted himself a virtual monopoly over Egyptian government.

Mr Morsi's concession had been a demand of his opponents. Yet it failed to address the key issue of Egypt's new constitution, which is due to be put before the nation in a referendum on Saturday. The draft charter was rushed through at the last minute by an Islamist-dominated assembly, with rights groups slamming the final document for its stipulation that Sunni Muslim clerics will be granted oversight for certain areas of legislation. - The Independent