David Walliams is taking the rest of the year off work as he prepares to undergo emergency back surgery.

The 'Little Britain' comic has been told by doctors he needs to rest after going into hospital this week to fix a disc he tore during a charity swim in 2011.

David, 42, told the Daily Mirror: ''Unfortunately the operation on my back is long overdue.

''The doctors have ordered me to rest for the remainder of the year so I can recover.''

The stand-up comedian has also apologised to fans for postponing his 'World of Walliams' book event, scheduled to be held at London's Palace Theatre on December 7, until March next year.

An insider said David is a ''workaholic'' and has performed every night during a recent two-month run of 'A Midsummer Night's Dream' alongside actress Sheridan Smith at the Noël Coward Theatre in London and also hosted the British Hairdressing Awards on Monday (25.11.13). But his relentless schedule has taken its toll and he now needs to rest after his operation.

The 'Britain's Got Talent' judge - who is married to 29-year-old model Lara Stone, with whom he has six-month-old son Alfred - has been on medication for back pain since his gruelling 140-mile swim along the River Thames which raised £2 million for charity Sports Relief.

David said after the challenge: ''It was really, really tough and the distance took it out of me.''