British Prime Minister Boris Johnson's fiancée Carrie Symonds has given birth to a baby boy, the couple have announced.

A spokeswoman for the prime minister and his partner said both mother and baby are "doing very well" after the birth in a London hospital this morning.

The spokeswoman 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."

Northern Ireland First Minister and DUP leader Arlene Foster was among those to offer their congratulations.

Mr Johnson and Ms Symonds' new son is the latest baby to be born to a serving British prime minister.

Downing Street has been home to a number of babies, with Tony Blair and David Cameron both adding to their families while in Number 10.