One store has seen sales 250% higher than last year

The Digital Radio Development Bureau (DRDB) said they were "absolutely astounded" at sales.

A spokeswoman said many retailers were reporting the radios to be their most popular gift, and some could not keep up with demand.

The DRDB said it expected up to 400,000 radio sold by the end of the year.

The spokeswoman said official UK figures could not be given out, but "tens of thousands" of radios had been sold each week since the middle of November.

"Sales everywhere have increased week on week," the spokeswoman said. "It is easily tens of thousands every week.

"We expected to sell about 100,000 in the run-up to Christmas. Not only is that number on the cards, we are sure we will beat it."

Department store John Lewis said on Monday it was selling 32% more radios compared to last week, 192% more than last month, and 250% more than last year.

Digital radio allows listeners to hear new stations such as the BBC's new music service 6music and BBC7, which broadcasts comedy and other speech programming.

It is seen as giving the listener better reception than normal analogue radios.