Chippenham MP Duncan Hames is hoping for an extra Christmas present this year, with his first child expected on December 25.
Mr Hames’ wife Jo Swinson, a Liberal Democrat under secretary of state and fellow MP, said on Wednesday she was expecting.
Mr Hames said: “It’s very exciting, we’re both looking forward to being parents.
“We had our 12 week scan last week, so we got to see the baby for the first time, and obviously we are very pleased it’s looking healthy.
“We don’t want to know about the sex, we would like to leave it as a surprise.”
Mr Hames has been the Lib Dem MP for Chippenham since 2010. Ms Swinson represents East Dunbartonshire, north of Glasgow.
The couple have a shared home in London where they will raise their child.
Mr Hames said: “We have arranged our anti-natal support in London so, unless baby decides otherwise, we expect the birth will be there. “There could be extra reasons to celebrate this Christmas.”