Boris Johnson and Carrie Symonds share pic of their baby boy Wilfred Lawrie Nicholas Johnson

Prime Minister Boris Johnson and his partner Carrie Symonds enter Downing Street as the Conservatives celebrate a sweeping election victory on December 13, 2019 in London. Photo / Getty Images

British PM Boris Johnson and partner Carrie Symonds have taken to Instagram to announce the name of their baby boy and share the first photo of their son.

"Introducing Wilfred Lawrie Nicholas Johnson born on 29.04.20 at 9am," Symonds wrote on her Instagram.

"Wilfred after Boris' grandfather, Lawrie after my grandfather, Nicholas after Dr Nick Price and Dr Nick Hart — the two doctors that saved Boris' life last month.

Wilfred Lawrie Nicholas Johnson is named in tribute to doctors who treated British PM. Photo / Instagram

"Thank you so, so much to the incredible NHS maternity team at UCLH that looked after us so well. I couldn't be happier. My heart is full."

Wilfred was born on Wednesday morning, just 16 days after Johnson, 55, fought for his life in intensive care with Covid-19.

Symonds also suffered from coronavirus but has since made a full recovery.

The baby was born healthy, several weeks before his due date. It is understood Johnson was there to witness the birth.

The British PM will take paternity leave later in the year, once the country has a better handle on the coronavirus crisis.

Wilfred is Symonds' first child but believed to be Johnson's sixth.

He has four children with ex-wife Marina Wheeler and another daughter from an affair with art consultant Helen Macintyre.