Carey Mulligan feels her best when she is "comfortable"

She told Vogue: "This is the comfiest I've ever been going to anything in my career, I think.

"I just feel the best when I'm comfortable-not just for when I'm slouching around the house, but for dinner or going to an event [too]. I always just want to feel [like] a slightly more polished version."

The 40-year-old actress - who has three children with husband Marcus Mumford - has been working with Prada for almost two decades and the fashion house feels like "family" to her.

She said: "They were really the first people who ever dressed me for anything, and they made my wedding dress.

"They feel like family to me. I always just feel really at home, and really myself [in] their clothes."

Her highlights of working with Prada over the years include the dress she wore to the Oscars in 2010, which featured miniature cooking utensils.

She said: "It was just so kooky, and weird and wonderful. That's probably my favourite."

And Carey was excited by her first campaign for the fashion house earlier this year, which was shot by Steven Meisel and saw her get to play a number of characters.

She said: "I absolutely loved the storytelling that went into it. All of those looks and those wigs, and the incredible makeup that Pat McGrath did. That was an incredible experience to make that."

The Promising Young Woman actress previously admitted she used to be "scared" of wearing designer gowns on the red carpet but becoming a parent made her care less.

She told the Sunday Times Style magazine: "When I was younger I was riddled with insecurities - red carpets made me feel like crying. I was scared of wearing big expensive dresses. It felt like a model's job and I didn't know what role I was meant to play.

"The first time I did press after I'd had my daughter she was one month old. I literally ran to the red carpet, did it, ran home, pulled off my dress and fed her in my Spanx and six inch heels."