Long-running BBC One sitcom My Family is set to be shaken up in the next series, with producers revealing one of its longest-standing characters is gay.

Show sources have told the Daily Mail that Michael, the youngest son of the Harpers - who is played by Gabriel Thomson (pictured) - will 'come out' to his parents Ben and Susan in a storyline at the start of the forthcoming tenth series.

This new plot development comes despite the fact that the character has been transformed from a geeky schoolboy into a bit of a heartthrob over the last few years. In many of the previous episodes Michael has been seen dating a string of girls, and has even previously had a long-term girlfriend called Fiona.

But now the family-orientated comedy is set to reveal the character is gay. This twist has been added following the arrival of a new team of writers, brought in by producers DLT Entertainment to make the often-criticised but still popular sitcom more 'edgy and relevant'.

A source told the Mail: "We were given a brief to turn the show into something a younger audience would relate to and watch. This is just one of the storylines we have come up with. It's handled very sensitively."

A spokesman for gay rights group Stonewall said: "It's refreshing that My Family will be reflecting modern Britain in their next series."

Despite being criticised as 'past it' and 'no longer funny', My Family is still Britain's most-watched current sitcom. The ninth series, broadcast last April, averaged over seven million viewers per episode.

Two new eight-episode series of My Family are currently in production. The new tenth series is due on air later this year, with the eleventh to air in 2011. Last year we reported that BBC bosses had cut the show's budget by 15 per cent, and this is the reason the two series are currently being made back-to-back.

BBC chiefs had initially also ordered a 10 per cent pay cut for stars Robert Lindsay and Zoe Wannamaker too, but it is now understood that the producers have managed to negotiate a less severe cut to ensure the sitcom could continue. Executive Producer Don Taffner Jr admitted: "The BBC proposals put the show at risk for a while."

Lindsay and Wannamaker have previously publically criticised the quality of the scripts, but have continued making the show anyway - presumably this is at least in part due to the money on offer. It is believed they're currently the best paid sitcom actors in Britain. According to The Mirror, Robert Lindsay is under strict instructions from his six-year-old son Jamie to carry on making the show. He told the paper that his son said to him: "You've got to keep filming it, Daddy, otherwise we won't be rich anymore."