Keira Knightley has spoken about juggling her busy work routine while caring for her six-week-old baby, saying she has to fit in “so much pumping” of breast milk.

The actress also claimed she has only brushed her hair roughly three times since having her second child with husband James Righton a month and a half ago, and said her neat and tidy appearance is “all smoke and mirrors”.

Knightley, 34, is on the promotion trail for the film Official Secrets, in which she plays Iraq War whistle-blower Katharine Gun and which had its European premiere in London on Thursday evening.

Official Secrets European Premiere – BFI London Film Festival 2019
Keira Knightley (left) and Katherine Gun attending the Official Secrets European premiere (David Parry/PA)

While being interviewed by BBC Breakfast, Knightley – who did not announce the arrival of her baby at the time – said: “Can I just say, this is about the third time since I’ve given birth that I’ve brushed my hair.”

She said she did not brush it herself, and that it was her “lovely” hairdresser who did it for her.

She added: “I was in my pyjamas when they got there, and this is somebody else’s dress.

“So it’s all smoke and mirrors today, which I’m super happy about, but I’ve just sort of been led here.”

Explaining her busy schedule, she said: “I’ve got six hours – so this is my work day – I’ve got six hours from when I left the house to when I get back. I’ve pumped (breast milk), and if I get back, I’ve got to get back before 6.30 because that’s the feed, it’s going to be fine, I’m going to make it.

“The only thing that might mean we don’t make it is Extinction Rebellion (protests), but me and my husband have talked about this and we’re like ‘Well, that’s OK’, so there is a bit of extra milk which I’d love not to use because it’s in the freezer and, you know, that could be tricky, but it is there.”

BBC Breakfast presenter Louise Minchin said it was “so refreshing” to hear that Knightley deals with things that “normal mums” go through.

Knightley replied: “What, pumping? Everyone has to deal with pumping, if you’re doing it, and if it’s working and you want to do that and you can, then, yes, we’re pumping.

“Pumping, so much pumping.”

She also joked that she and Klaxons rocker Righton have told people visiting their home while they care for their newborn: “If you’re coming round, bring food.”

Knightley and Righton, who married in 2013, are also parents to four-year-old daughter Edie.

In her latest big-screen venture, Knightley plays Government Communications Headquarters (GCHQ) translator Gun, who in 2003 leaked a classified email which urged spying on members of the UN Security Council to push the Iraq War.

Keira Knightley and James Righton
Keira Knightley and James Righton in 2015 (Dominic Lipinski/PA)

In doing so, she risked her career and put her life on the line.

Knightley said she does not think she would be “brave enough” to do what Gun did.

She added: “And I think that’s what’s extraordinary about this story, is that you realise most people don’t, most people look the other way, and it’s completely understandable to look the other way because you want to save yourself and you don’t want to completely derail your life.”

The star-studded British cast also includes Ralph Fiennes, Matt Smith and Matthew Goode.

Official Secrets is released in UK cinemas on October 18.