Small protests have been held in the capital in the past week to support Tunisia Anti-government activists in Egypt are preparing for a rare day of protest, inspired by the recent political upheaval in Tunisia.
Organisers have called for a “day of revolt against torture, poverty, corruption and unemployment”.
But the government has warned they face arrest and is calling its supporters out in a counter-demonstration.
Weeks of unrest in Tunisia eventually toppled President Zine al-Abidine Ben Ali in Tunisia earlier this month.
The events in Cairo are being co-ordinated on a Facebook page – tens of thousands of supporters have clicked on the page to say they will take part.
“Our protest on the 25th is the beginning of the end,” Reuters quoted the organisers as saying.
“It is the end of silence, acquiescence and submission to what is happening in our country. It will be the start of a new page in Egypt’s history – one of activism and demanding our rights.”
The BBC’s Jon Leyne in Cairo says event is a direct response to the campaign that ousted President Ben Ali of Tunisia, in which the internet also played an important part.
But there is bound to be scepticism about exactly how many will actually turn up, say our correspondent.
They know they could face a tough response from the police, who often break up protests with violence.
In a statement, the government’s security director in the capital said: “The security apparatus will deal firmly and decisively with any attempt to break the law.”
Egypt’s political opposition is also divided – one leader, Mohamed El-Baradei, has called on Egyptians to take part, but the Muslim Brotherhood, still the most powerful opposition movement, has been more ambivalent.
Egypt has many of same social and political problems that brought about the unrest in Tunisia – rising food prices, high unemployment and anger at official corruption.
But protests so far have only been small-scale and correspondents say a similar political upheaval is unlikely.
This article is from the BBC News website. © British Broadcasting Corporation, The BBC is not responsible for the content of external internet sites.