Egyptian President Mohammed Mursi has blamed "enemies of Egypt" for paralysing its new democracy.

In a speech this evening, he criticised street protests ahead of mass rallies against Islamist rule this weekend.

Mr Mursi’s televised address admitted errors and offered reform but was otherwise uncompromising in its denunciation of those he blamed - some of them by name.

Earlier, two people were killed and scores wounded in the latest factional street clashes that many fear may presage a violent showdown this weekend.

After an hour, Mr Mursi had offered nothing that would persuade his opponents to call off mass demonstrations they have called to demand his resignation and new elections.

The army has warned it may step in if politicians do not reconcile.

Interrupted by occasional cheers from Islamist supporters, Mr Mursi told an audience that also included generals and officials that many of the difficulties of his first year in office were due to the continued influence of corrupt figures who had been appointed before the 2011 revolution by Hosni Mubarak.

"I took responsibility for a country mired in corruption and was faced with a war to make me fail," he said, naming some senior officials, including the man he beat in last year's presidential run-off, as well as neighbourhood "thugs".

Mr Mursi acknowledged the hardships many of the young who saw hope in the revolution have had in an economy mired in crisis and offered them reforms and, in time, a higher minimum wage.

"Political polarisation and conflict has reached a stage that threatens our nascent democratic experience and threatens to put the whole nation in a state of paralysis and chaos," he said.

"The enemies of Egypt have not spared effort in trying to sabotage the democratic experience."

"I stand before you as an Egyptian citizen, not as the holder of an office, who is fearful for his country," he said before saying he would review his first year in office, which began on 30 June - the date protesters have chosen to rally.

Fears of a violent stand-off in the streets between Mr Mursi's Islamist supporters and a broad coalition of the disaffected have led people to stock up on food.

Long lines of cars outside petrol stations have snarled roads in Cairo and other cities.

Some observers fear Egypt may be about to erupt again, two years after the revolution that toppled Mubarak.

Politics are polarised between Mr Mursi's disciplined Muslim Brotherhood and disparate opponents who have lost a series of elections.

The deadlock has contributed to a deepening economic crisis and the government is running out of cash.