'Vicious' is set to finish with a one-off special next year.

Sir Ian McKellen

Sir Ian McKellen

The British sitcom, which stars Sir Ian McKellen and Sir Derek Jacobi as two gay men, may have only been running for two series but is expected to bow out for good in January with an extended final episode following a drop in ratings.

A spokesman for the show told The Sun newspaper: "It's been an absolute delight to see Ian McKellen, Derek Jacobi and Frances de la Tour bring alive these wonderful characters on screen for ITV viewers. We're over the moon all the cast are returning for one final special."

The forthcoming special will be filmed tonight (23.12. 15) at the London Studios in Waterloo as the audience see the main cast - including Frances de la Tour, who plays the couple's friend Violet - join forces for one last time.

The episode will follow on from the finale of series two, which saw Freddie and Stuart (played by McKellen and Jacobi respectively) tie the knot after 50 years together.

Details surrounding the special will be announced in early January, while the definite future of 'Vicious,' which proved highly popular in the US, will also be confirmed.