The Mudbound and Collateral star said she had never worked on a film that had childcare on set and that many pregnant actresses have to "hide it".

Mulligan has two children with husband Marcus Mumford. "It's incredibly difficult. Childcare is so expensive," she told the Radio Times.

"I've never, ever been on a set where they have childcare."

She added: "But I've been on lots of sets where lots of people have very young children."

If childcare was available on film sets, "it would make it possible for a lot of talented people to come and do their job", she said.

"At the moment, it's limiting."

'Incredibly complicated'

Mulligan told the magazine that her daughter Evelyn, who was born in September 2015, was with her on the set of her 2017 Oscar-nominated film Mudbound.

She said that on her new film Wildlife, "loads of the crew had kids, but they had to arrange childcare".

She added: "It's always incredibly complicated."

She filmed BBC Two drama Collateral while pregnant with her son Wilfred, who was born last summer, after the programme's writer Sir David Hare re-wrote her character to make her pregnant.

But she said: "I don't think we're at the level where it's acceptable across the board yet. I think if people can hide it, they do."

 McElhone will star alongside Sean Penn in The First

Mulligan stars alongside Jake Gyllenhaal in Wildlife as a 1960s wife who begins a relationship with another man as her marriage crumbles.

In contrast, fellow British actress Natascha McElhone has said in a separate interview that she found the creator of her latest TV series "hugely generous and understanding" about her childcare situation.

"My kids are the centre of my life, and work is something that I fit around them," she said.

Her husband Martin Kelly died of heart failure 10 years ago when she was pregnant with their third child.

McElhone said she had to carefully consider whether to take a role in The First, written by House of Cards creator Beau Willimon.

"Beau is hugely generous and understanding about the complexity of our lives, so that was one of the first things we spoke about when we met, whether it was even possible for me to do this job, because I need to be home, pretty much all of the time," she said.

"They shot a lot in my kids' school holidays, so my kids came out [to Louisiana] for a month, which was great. And the rest of the time I commuted. It would be a week shooting and then I would just come back and then go back out a few weeks later."