Speaking at the premiere, the American Hustle star said: “It’s not important to me… I’m completely willing to play a vulnerable mess.”

Joy has been nominated for a Golden Globe, while Jennifer has been shortlisted for the best actress prize.

There is speculation that she could also be in line for a second Academy Award, but she said: “It should be Brie Larson’s year. But [another Oscar] would be very exciting.”

Brie’s star turn in Room has put her among the front-runners, however she may face stiff competition from Jennifer in her role as Joy Mangano.

Joy was a struggling single mother of three children when she invented the Miracle Mop, a self-wringing household tool which became hugely popular in the US.

She went on to build a business empire, thanks in part to Neil Walker, a telesales executive played by Bradley Cooper.

The flick, which is also stars Robert De Niro as Joy’s father, opens in cinemas on January 1.