PARIS: Penelope Cruz will never marry boyfriend Javier Bardem, because she doesn't believe in the concept.

The Oscar winner does plan to start a family one day, but hints it could be at the expense of her acting career - because she wants to be the best mum in the world.

Cruz reveals, "I want to have babies one day but not right now. When I do it I want to do it really well. I want it to be my best project in life.

"I don’t know if I believe in marriage. I believe in family, love and children."