Gordon Brown and his wife Sarah are expecting a baby in October, it has been announced.
The Browns called their first child an "inspiration"
News of the pregnancy comes just over a year after the couple's first child, Jennifer Jane, died when she was only 10 days old.
A spokesman for the chancellor, who delivers his Budget on Wednesday, said: "Sarah and Gordon Brown are expecting a baby in
"This is clearly good and welcome news and Sarah is fit and well.
"Mr and Mrs Brown will not be issuing any further statement."
Jennifer Jane Brown was born in December 2001 at Forth Park Hospital in Fife seven weeks premature.
Born 20/02/51 in Glasgow
1983 becomes MP for Dunfermline East
1987 joins Labour's frontbench
1992 shadow chancellor
Blair appoints him chancellor after 1997 Labour victory
Marries PR executive Sarah Macaulay in 2000
She died at the Royal Infirmary in Edinburgh a little more than a week later after suffering a brain haemorrhage.
At the time, Mr Brown, 52, said she had been an "inspiration" to both him and his wife, whose lives would not be the same again.
The chancellor and his 38-year-old wife, who works under her maiden name of Sarah Macaulay, were married in August 2000 at a private ceremony in North Queensferry, Fife.
Ministerial births in Downing Street have become more commonplace, with Tony Blair in 2000 becoming the first prime minister in 150 years to father a child while in office.