Oscar winner Emma Thompson has risked the wrath of working mums everywhere by insisting it's impossible to be a great mum and a career woman at the same time in a new interview.

The Saving Mr. Banks star, who is mum to a 26-year-old adopted son and a teenage daughter, took a year off from acting to concentrate on perfecting her parenting, and now she's encouraging other working mothers to follow her example.

She tells Britain's Daily Mail, "You can't be a great mum and keep working all the time."

Thompson tells the publication her year away from Hollywood was "a birthday present to myself," adding, "I didn't actually act or write. I was just a mum... I taught drama at my daughter's school, cooked meals and had fun.

"I highly recommend others to do the same if they can afford it... Motherhood is a full-time job. The only way I could have continued working would have been by delegating the running of the home to other people. I never wanted to do this, as I find motherhood profoundly enjoyable."