A spokesman for the British Prime Minister, Mr Blair, confirmed last night that Mrs Cherie Blair is expecting a baby. "Following inquiries from the Mirror newspaper I can confirm Cherie Blair is pregnant," the spokesman said. "The prime minister and Mrs Blair had hoped to announce this later in the pregnancy as only a small number of family and friends and Number 10 officials are aware. They are delighted at the news which came as a total shock. The baby is expected in May."
Mr Blair (46) has always said his family are the most important things in his life and keep his feet on the ground.
In July he told BBC 1's Newsround he would have liked to have more children. "We would have had five if, well, if we had carried on, I suppose," he said. "I think big families are great."
Mrs Blair (45) has also stressed the importance of the family in their lives and lists among her recreations: "Keeping fit and enjoying my children."
The couple, who are Roman Catholic, married in 1980 and gave no hint of the news yesterday as they went about what are routine duties for a prime minister and his wife.
Mrs Blair hosted one of her regular tea parties for MPs and the children of constituents from a number of West Country constituencies at Downing Street.
Mr Blair gave a speech to the Institute for Public Policy Research at the Design Council in London and then a series of media interviews on Ken Livingstone's bid to become mayor of London.
Mr Blair was in combative mood in the interviews, delivering a series of warnings about the dangers of Mr Livingstone but he was relaxed off-camera when he chatted to reporters.
It is understood Mr Blair first knew of the pregnancy during the party conference season but he wanted to keep it private until next year.
The Blairs have three children - two teenage boys and an 11-year-old girl.