Hilary Duff has slammed critics who have dared to criticise her post-pregnancy figure.

The 24-year-old gave birth to son Luca just three months ago but received a barrage of hateful messages when she was pictured in a bikini last week.

The starlet, who is married to NHL player Mike Comrie, told In Touch that those people should have the courage "say it to my face."

"I'm not perfect, but I feel fantastic," Hilary told the publication. "This is how it goes for most women when the weight doesn't fall off overnight."

The actress revealed that she has a work out regime which she adheres to "a few" times a week and also takes in spin classes and private training sessions.

Bloggers had posted that Hilary looked "gross" and that she "turned into her mother."

"I don't care what people say," Hilary said defiantly. "I'm not back to where I want to be, but I'm not stressing it."

Hilary added that Mike "doesn't care" about her extra pounds and "even during my pregnancy he thought I was beautiful."