1m homes to lose ITV, C4 and Five

net1

Sky is preparing to withdraw the three main commercial TV channels from up to a million homes in a dispute that threatens the government's digital broadcasting plans.

ITV1, Channel 4 and Five will "go dark" because the BBC has decided to stop paying for the viewing cards that decode the satellite signals.

Chris Bryant, Labour MP for the Rhondda, called on the government to step in and resolve the issue. He said the affected viewers would have to switch back to their analogue aerials to receive the main channels - against the government's policy of converting the whole country to digital TV by 2010.

Until now, the BBC has paid for the viewing cards that decoded the satellite signals for all the "free to view" channels - the BBC's services, the three terrestrial commercial networks and stations such as Sky News, CNN and Turner Classic Movies.

But yesterday the BBC started broadcasting its services unencrypted, after moving to a new satellite. ITV, Channel 4 and Five are unwilling to take up the cost.

According to independent television commission estimates, 660,000 households have a set-top box connected to a satellite dish but do not subscribe to Sky. Some analysts put the figure nearer a million.

Sky was in the process of upgrading the cards before the BBC announced its decision to broadcast "in the clear" - customers with new cards will not be affected.

Analysts say ITV has the most to lose: the government offers it a financial incentive for every viewer it converts to digital.