Key decisions over the timing of the switchover to digital TV across Britain will be taken by the end of this year, Culture Secretary Tessa Jowell said today.

But the vital issue of whether the Government will subsidise set-top boxes or cable connections for those who opt not to update their TVs themselves will not be settled for some time after that, she suggested.

Media regulator Ofcom has proposed a timetable for the analogue signal to be switched off region by region between 2008 and 2011, when Britain will be fully digital.

But the Government has yet to commit itself to final details for the plan, which is likely to spark opposition from viewers happy with the existing five terrestrial channels and resentful of having to buy new electronic equipment to carry on watching TV.

Ms Jowell today said it would be “unthinkable” for anybody to be left unable to watch TV because of the switchover, and said that the needs of vulnerable people, particularly the elderly, would be uppermost in her mind when the final decisions on how it happens are made.

But she stopped short of offering Government support for the purchase of set-top boxes – currently on sale from around £40 – or the adjustments to aerials that may be needed to receive digital signals.

“I expect decisions to move quite rapidly between now and the end of the year on the exact timing and the phasing,” she told BBC1’s Breakfast With Frost.

“There won’t be a national switchover day. What will happen is that regions will switch one at a time.

“All the undertakings have to be to ensure a very clear transition for people, and very particularly elderly people, vulnerable people, people who may find it hard to cope with new technology. We’ve got to make sure that before we press the button, their interests are looked after.”

Asked if needy people would be helped with the cost of switching to digital, she said: “That is not yet certain. We have seen the price of boxes come down. You can now get a box for under £40.

“We are not at the point yet of making decisions about whether we need to give free set-top boxes.

“Those decisions will be taken, but they are decisions for three or four years’ time, not now.”

Ofcom’s recommendations, published last month, envisage the West Country, Wales and the far northern counties of England going digital in 2008, followed by the North-West and Scotland in 2009, Midlands and Yorkshire in 2010 and London and the South-East in 2011.