Activists in Egypt are set to mark the first anniversary of the overthrow of President Hosni Mubarak with a strike and day of civil disobedience.
The action is intended to put pressure on the ruling Supreme Council of the Armed Forces (Scaf) to hand over power to a civilian authority.
In a statement issued on Friday, Scaf accused what it called "plotters" of trying to undermine the Egyptian state.
It warned they would bring Egypt "chaos and destruction".
Scaf has promised to hand over power after presidential elections in June, but opposition groups have been calling for an immediate transfer of power.
The Muslim Brotherhood, which won the largest number of seats in recent parliamentary elections, has not backed Saturday's protest.
State television said transport workers would not be going on strike. The headline in state-owned newspaper al-Ahram read: "The people reject civil disobedience".
The ruling generals - who have lost popularity since they took over last year - said they would not yield to threats, or bow to pressure to speed up the transition process.
Activists are now planning to begin a campaign of strikes in universities and workplaces.
Mr Mubarak stepped down on 11 February last year after 18 days of street protests in which hundreds were killed.
He is on trial accused of ordering the killing of demonstrators, charges he denies.
The military took power under the leadership of Field Marshal Mohamed Hussein Tantawi. Following a protracted election process, a new parliament dominated by Islamist parties held its first session earlier this month.
However, protests and unrest have continued, most recently with the deaths of 74 people after a football match in the city of Port Said and at least four others in ensuing demonstrations.
In its statement broadcast on Friday evening, Scaf warned against conspiracies, saying the army had played a vital part in the revolution.
"We are facing plots against the nation aiming to undermine the institutions of the Egyptian state, and to topple the state itself so that chaos reigns," the message said.
Scaf also confirmed that presidential elections were on course to take place in June.
Thousands of protesters demonstrated outside the ministry of defence on Friday, calling for a swifter transition to civilian rule.
In the year since Mr Mubarak was toppled, Egypt's economy has been battered. The country is haemorrhaging about $1bn (£638m) a month in foreign currency reserves, and the Egyptian pound has fallen to new lows.