The reign of Egypt's Muslim Brotherhood, political home of struggling President Mohamed Mursi, will end within a week, former Egyptian prime minister Ahmed Shafik said

Dubai: The reign of Egypt's Muslim Brotherhood, political home of struggling President Mohamed Mursi, will end within a week, former Egyptian prime minister Ahmed Shafik said on Monday.

Shafik, whom Mursi narrowly beat in a presidential run-off vote last year, also did not rule out seeking the presidency once again.

He was speaking before Egypt's armed forces issued a virtual ultimatum to Mursi by calling on the nation's feuding opposition to agree on a roadmap for the country's future within 48 hours.

"We are going through a stage, which we knew we'd inevitably have to go through. It is not strange. The failure of the Brotherhood cannot be withstood and has led to catastrophes of all kinds and it was completely expected," Shafik told Reuters from Abu Dhabi, capital of the United Arab Emirates.

"In my expectation, I think that this regime will completely end its relation with Egypt within a week and will end its relationship forever within the region ... Yesterday the regime's (reign) almost ended," Shafik said.

Millions of Egyptians took to the streets on Sunday to demand that Mursi quit, in crowds that were far larger than the Arab Spring uprising that toppled Hosni Mubarak in 2011.

Shafik was the last prime minister under Mubarak.

An outspoken critic of Mursi, Shafik said the Brotherhood had "led us to catastrophe in less than a year".

Mursi specifically criticised Shafik in a speech he gave last week ahead of the scheduled protests.

The Muslim Brotherhood's critics have accused the Islamist movement of using a series of electoral victories to monopolise power. Egyptians are also uneasy with a failing economy that has seen tourism and investment dry up, high inflation and fuel and power shortages.

Shafik, who is on an official watch list over graft charges which he has dismissed as political, did not rule out his return to Egypt to seek the presidency once again.

"For sure, I can do this (run as president) ... my voters are present and their numbers have increased," he said.

"This talk is before its time. But there's no doubt that it's one of the possibilities ahead of me," Shafik said.

The former air force pilot and prime minister, who along with his daughters and grandchildren fled to Abu Dhabi in June 2012 after Mursi was declared president, said he had been coordinating the street protests.

"No doubt, even though I've been sitting here (Abu Dhabi) I've had a role in what's happening," he said.

"I'm in continuous coordination with colleagues in Cairo. The coordination is over 24 hours. It's as if I'm living in Egypt," without giving details of the actual measures.

In a military career spanning four decades, Shafik served as a senior fighter pilot under ousted President Hosni Mubarak's command, and was credited with shooting down two Israeli aircraft in the October 1973 war.

(Reporting by Mahmoud Habboush, Amena Bakr and Yara Bayoumy; Writing by Yara Bayoumy)