Boris Johnson's fiancee Carrie Symonds pictured sporting baby bump

Boris Johnson's pregnant fiancee Carrie Symonds has been pictured for the first time showing off her baby bump while attending a women's day event.

It is the first time she has been spotted at a public event since announcing she was expecting a child.

The 31-year-old was photographed alongside the prime minister at a reception held at Number 10 on Thursday to celebrate International Women's Day, which takes place on Sunday.

No statement was released alongside the pictures, which were posted on Twitter by Downing Street.

The post said: "Tomorrow it's #InternationalWomensDay. We celebrated earlier this week by hosting a reception at Downing Street."

Ms Symonds' growing baby bump - and a large engagement ring - were visible in the pictures released on Saturday morning.

The pair announced last weekend that they were engaged and expecting a baby in the "early summer", with Ms Symonds telling her followers on social media she felt "incredibly blessed".

She said she and Mr Johnson, 55, got engaged at the end of last year "and we've got a baby hatching early summer".

Before that, Ms Symonds had not been seen in public since the general election in December.

Mr Johnson said he will almost certainly take paternity leave when his new child is born later this year.

Earlier this week, it was reported that Mr Johnson said there remains "so much more to do" to ensure equality between men and women as he addressed the reception to mark International Women's Day.

The prime minister said the "automatic assumption" that men are "going to be of a certain position in life" still needed to be challenged, as he told an audience of schoolgirls inside Number 10 how he had learnt that sexism is "complete rubbish" at an early age.

Speaking alongside Olympic gold medallist Dame Kelly Holmes and mathematician Anne-Marie Imafidon, Mr Johnson said: "It's fantastic to be up on stage here with quite intimidating talent in many ways...

"I'm left miles and miles behind and yet historically men have enjoyed this kind of automatic assumption that they are going to be of a certain position in life - and that still needs to be challenged.

"And yes it's fantastic to celebrate the achievements of women today, but there is so much more to do. And I look around the world, I see a real gulf and we in this country are making huge progress, though there is still a long way to go.

"But there are too many countries where girls just don't get the treatment, the education, the advancement, the encouragement that they need by comparison with boys, and that's in my view the single biggest issue that the world could address."

Mr Johnson said he had "any kind of sexism kicked out of me at a very early age" because his sister, Rachel, who is a year his junior, was "just as good as I was, if not better, at things like climbing trees, and swimming and reading".

"So I realised that this whole sexism thing was complete rubbish."

Mr Johnson has four grown-up children with his second wife Marina Wheeler, with whom he recently reached a financial settlement over his divorce.