Coming ahead of contract negotiations, the bonus is thought to be in response to the cast's anger at receiving glass paperweights marking the show's 100th episode.

The stars, David Schwimmer who plays Ross, Matthew Perry (Chandler), Courteney Cox (Monica), Lisa Kudrow (Phoebe), Matt LeBlanc (Joey) and Jennifer Aniston (Rachel), are said to have left their bosses in no doubt that far grander gifts had been expected.

They later came up with a list of demands said to include chauffeur-driven cars, personal assistants and personal trainers.

The cast is also said to have asked for their salaries to be doubled to £125,000 per episode - a move which would take their annual earnings from the hit show to more than £2.6m.

Friends, which is screened in the UK on Sky One and Channel 4, has a history of salary disputes. Two years ago, the cast threatened to go on strike unless they received pay increases.

At the time the actors were locked into their original contracts paying them £1,000 an episode.

However, considering the amount of money the chart-topping sitcom makes for Warner Bros, the television industry considers the cast relatively underpaid. Colleagues on the medical drama ER earn up to £200,000 an episode.