As strikes go, this one takes the cake ... or rolls out the barrel, and must have Australian-born Crown Princess Mary raising an eyebrow.

Scores of Carlsberg workers have walked off their jobs to protest the Danish brewer's new limits on beer drinking at work.

At work in the Carlsberg factory.

Carlsberg spokesman Jens Bekke says 250 warehouse and production workers and truck drivers went on strike on Thursday on the second day of a rebellion against the new rules, which state workers can only drink beer in the canteen during the lunch break.

Bekke says previously Carlsberg had no restrictions on beer drinking as long as employees didn't get drunk on the job.

He says truck drivers are exempt from the new rules and are permitted to drink three beers outside the canteen. But they still went on strike in sympathy with their colleagues.

Alcohol ignition locks on the trucks prevent them from driving drunk.

AP