Dame Thora Hird's last role is a BBC7 highlight

The station will continue to broadcast around the clock after the anniversary, on Monday. The station previously went off air at 3am.

In January it will feature the last radio performance by Dame Thora Hird, in Alan Bennett's The Last of the Sun.

The play was recorded in June 2002, just nine months before her death at the age of 91.

"Knowing this was likely to be the last work that Thora would do, I wanted her to go out with a bang and certainly with a laugh, even if it was a dirty one," Bennett said.

"At the finish Thora goes down with all her flags flying, game to the last," the playwright said.

The play saw Dame Thora play Dolly, a woman ending her life in an old people's home. It included her singing a song she had first learnt when she was 16.

BBC 7 is a speech-based digital station, featuring drama and comedy from the BBC archives as well as new commissions.

Since its launch last December, the station has attracted 347,000 listeners a week.

"BBC 7's fresh on-air sound and its addictive mix of archive comedy, drama and books is proving a great hit with our listeners," said head of programmes Mary Kalemkerian.

"So we decided to give them more of what they like and extend broadcasting right through the night," she said.