A spokesman for Boris Johnson and Carrie Symonds said: "The Prime Minister and Ms Symonds are thrilled to announce the birth of a healthy baby boy at a London hospital earlier this morning. Both mother and baby are doing very well.

"The PM and Ms Symonds would like to thank the fantastic NHS maternity team."

Health Secretary Matt Hancock tweeted: "So thrilled for Boris and Carrie. Wonderful to have a moment of unalloyed joy!"

Labour leader Sir Keir Starmer tweeted: "Wonderful news. Many congratulations to Boris Johnson and Carrie Symonds."

Former Conservative leader Iain Duncan Smith tweeted: "Congratulations @BorisJohnson & @carriesymonds such wonderful news! Baby boy!"

Chancellor Rishi Sunak tweeted: "Great to hear Downing Street is getting a new resident.

"Congratulations to @BorisJohnson and @carriesymonds on the birth of their son."

Former chancellor Sajid Javid tweeted: "Congratulations @carriesymonds @BorisJohnson. Such wonderful uplifting news!"

Sir Ed Davey, the acting leader of the Liberal Democrats, tweeted: "Many congratulations to the PM & Carrie Symonds on the birth of their son!"

It is understood the PM was present throughout the birth, which took place in an NHS hospital in London.

The Prime Minister's father, Stanley Johnson, told the PA news agency he was "absolutely delighted" and "thrilled" by the birth of his grandson.

Scottish First Minister Nicola Sturgeon tweeted: "Some good news - sending congratulations to Carrie and the PM. And wishing health and happiness to the wee one."

The Archbishop of Canterbury, Justin Welby, tweeted: "Congratulations and prayers for @BorisJohnson and @CarrieSymonds as they welcome their son into the world. Wishing them every blessing and happiness."