Gamal Mubarak brushes off questions about his presidential ambitions
Opposition groups in Egypt have started a campaign to block President Hosni Mubarak from passing power to his son.
The campaign is called Mayehkomsh?, loosely translated as "He shall not rule". It is organised by Ayman Nour, a presidential challenger in 2005.
Organisers said it was a battle against the political system, rather than a campaign aimed at Gamal Mubarak.
President Mubarak, 81, has not said if he will seek another term, sparking fresh questions about his successor.
Speculation has been common in recent years that Gamal - a leader of the ruling National Democratic Party - is being groomed for the role, although he has always denied having ambitions to rule Egypt.
Senior government officials have ruled out what they call a dynastic succession, although he could be candidate in elections.
Opposition groups say the election system is so stacked in the NDP's favour it amounts to the same thing.
"Our constitution is for a republic not a kingdom," said Mr Nour at a news conference in central Cairo.
"This is a campaign to confront this irregular... illogical state where a president-in-waiting is practising all the duties of the president already," he add.
Mr Nour fought in the 2005 presidential election, in which President Mubarak won a fifth consecutive term in office.
It was the country's first contested presidential poll, but he was jailed weeks later for alleged forgery, a charge he strongly denied.
He was released in January 2009 on health grounds, but under Egyptian law he can no longer run for public office because of his criminal record.
Wednesday's launch event was attended by representative from across the opposition spectrum, including the Muslim Brotherhood.
The Muslim Brotherhood is official banned, but remains the largest and most organised opposition force, with one-fifth of MPs in the parliament who stand as independents.