By James Ingham
BBC News, Caracas
Venezuela's top court has allowed the government to take control of private TV transmitters as it prepares to replace commercial with state-run TV.
The president says he has the right to silence the channel
Radio Caracas Television, a station critical of the government, is being forced to stop broadcasting on its public frequency.
Tens of thousands of people are expected to protest against the decision this weekend.
Government supporters are planning a separate show of strength.
The court's decision will allow the Venezuelan government to demand that RCTV hands over its network of transmission sites the moment it comes off air.
'Path of dictatorship'
From that moment, midnight on Sunday, Venezuelans will be able to tune into a new state-run channel.
Of course that is what has angered so many thousands of people here.
Protesters say President Hugo Chavez is limiting freedom of expression and taking the country down the path of dictatorship.
But the president maintains he has the right to silence a channel that he says actively tries to undermine his government.
With huge protests planned this weekend, security in the city is tight.
In a show of force, dozens of military vehicles have filed through the roads of Caracas in a slow-moving cavalcade.
Mr Chavez has warned his followers that the country is under threat from those opposed to his rule.