The actor was formally sentenced yesterday in Los Angeles, California, and his lawyer said he would begin serving the prison term immediately.

Sutherland, 40, was also ordered to spend five years on probation and to complete an 18-month alcohol education programme and six months of weekly therapy sessions. He was fined $510 (£250).

"There will be no early release and no good time work time. He will serve the entire sentence," said Nick Velasquez, a spokesman for the LA city attorney.

In October, Sutherland pleaded no contest - the equivalent of a guilty plea - to a charge of driving with a blood alcohol level above the legal limit.

Thirty days of his sentence were for failing a blood-alcohol test after his arrest in September in west Los Angeles.

The remaining 18 days of the sentence were for violating his probation from a previous case.

In 2004, the actor was sentenced to five years probation and 50 hours of community service and was ordered to complete an alcohol program in connection with another drink-driving arrest.

Sutherland had been pencilled in to complete his jail sentence in two parts, in order to allow filming on 24 to continue, but the US screenwriters' strike means production has been suspended.

The Canadian actor, the son of the screen star Donald Sutherland, won an Emmy award last year for his role as the counter-terrorism agent Jack Bauer on 24.