As the administrators struggle during the next two weeks to rescue something from the troubled condition of ITV Digital, I hope that everyone - government and broadcasters alike - will be putting some thought into what public policy issues arise about the wider future of digital television.

Two fundamental aims should remain firmly in place. First, we must continue to press for a wholesale transition from analogue to digital in due course. Already, some 40 per cent of households have made that change, far ahead of anywhere else in the world. The objective of achieving switchover - with all the advantages for viewers in terms of choice and quality, coupled with the potential economic advantages of being first movers - is still an eminently desirable one, even if it may now become more difficult to achieve.

And second, we must secure a genuine choice for consumers between different digital platforms. The now-fragile nature of terrestrial subscription television, coupled with the huge problems of cable, could potentially threaten this objective. It may of course yet happen that financial deals are re-arranged and ITV Digital itself survives. But we need to prepare for the eventuality that it doesn't. And the overriding public interest in such circumstances, surely, must be to secure the survival of the digital terrestrial platform itself.

I would suggest that three steps are needed in order to do so. The first is something the government could and should be doing anyway: turning up the power on the digital signal that's being transmitted. One of the problems that has dogged digital terrestrial television has been the limited proportion of the population that is able to receive it through their aerials. Improving the signal means that more people can be reached.

The second is a joint task for government, broadcasters, retailers, and manufacturers. There must be a clear and simple "explanation campaign" to lead the public through the confusing maze that is digital television. There is a need to demystify digital for ordinary consumers, who are interested at heart in programmes, not in platforms or technologies. Making sure that they have clear information about the choices that are available to them ought surely to have a high priority.

The third step will become essential if the administrators are ultimately unsuccessful. If the main subscription option for digital terrestrial disappears, it will be necessary to ensure that the platform can still be attractively offered to consumers as a largely free-to-view environment. The BBC, ITV, Channel 4 and Channel 5 must get together to prepare precisely such an offering. We know that preliminary talks have already taken place, but they must now assume a greater urgency, and they must involve all the public service broadcasters, not just the BBC. If a "cheap and cheerful" set-top box can be made available, providing a plug-in-and-play option at a reasonable one-off cost to viewers, it will provide a real terrestrial alternative to the satellite or cable platforms that are, by their nature, either expensive or only available in limited places. It would be even better if the box allowed the possibility that in future it could carry a small number of subscription services as an upgrade to the free-to-view content.

I have believed for some time that there is only a certain portion of the population who want to have a choice of 200 or 300 channels, albeit focused on sport, movies and cartoons. There are many more who want a little bit more than the current free analogue range of five channels, but are still only interested in a modest selection, at no cost or modest cost. Perhaps if ONdigital and ITV Digital had aimed themselves at those viewers from the start, history might have been different. With hindsight, we can see that trying to compete head to head with Sky was always in danger of ending in tears. Fashioning, now, a different product, aimed at a different potential audience, may yet be possible.

When all is said and done, ITV Digital has - at huge cost to both Granada and Carlton - kept digital terrestrial television alive.

It may now need to be in a different form, but we must ensure it continues to live.

Chris Smith MP is the former secretary of state for culture, media and sport. He is also senior adviser to Walt Disney Co Ltd