The move was welcomed by digital television companies such as ONdigital and Sky. The plan includes a number of targets that would have to be met before switch-off occurred between 2006 and 2010.
"When 70 per cent of consumers have access to digital equipment, we will know that the significant milestone has passed," Mr Smith told the Cambridge Television Festival of the Royal Television Society.
On current targets the 70 per cent point is expected to be passed by 2006, according to industry sources. It is expected to trigger an exact date for total analogue switch-off.
A spokesman for an alliance of digital companies said he saw no problem in reaching the target. Mr Smith, however, said full switch-over will only be completed when 95 per cent of the country's homes have changed to digital.
The target raises the possibility of the remaining 5 per cent - 1.1 million homes - being unable to receive any television. But the digital companies' spokesman said plans to deal with the remaining 5 per cent were already being made.
"By the time we reach that point, set-top boxes will be small and cost only pounds 25 or so - we will be able to give them away, or even post them through letterboxes," he said.
Mr Smith said the television industry should pass two crucial core tests before analogue is fully switched to digital: first, to make sure that everyone can get the main free-to-air channels digitally and has access to the Internet; and second, that switching to digital must be affordable for nearly all people.
As part of a future review process, he said, he would set up a viewers' panel to assess evidence from industry, broadcasters and government on how the digital targets were being met. The panel would be drawn from all parts of the UK and include people proposed by the Voice of the Listener and Viewer, the Consumers' Association, the National Consumer Council and organisations representing pensioners.
Mr Smith stressed that he wanted the digital revolution to succeed. Attention is now focused on whether he will endorse proposals for a pounds 19 digital licence fee for the BBC, which could hamper the television industries in meeting the 70 per cent and 95 per cent take-up rate targets for digital.
Mr Smith will decide on the fee by the end of the year. He said yesterday: "Let me make one thing clear: there should be no automatic presumption that I will accept all the [Gavyn Davies] recommendations."
He also urged BSkyB and ONdigital to resolve a dispute over whether ITV should appear on Sky's digital services.
Mr Smith said that early in the next Parliament legislation would be brought in to rationalise the various regulators of television - including the Independent Television Commission, Oftel and the Office of Fair Trading - and to reduce the amount of content regulation of television.
The message to organisations such as the Broadcasting Standards Commission seems to be that, while in future there will be strict rules on impartiality for TV, positions on taste and decency will be relaxed.Reuse content