The estranged wife of Barnaby Joyce says her family feels “deceived and hurt” following reports the Deputy Prime Minister is expecting a baby with a former member of his staff.

Reports of the impending birth of Mr Joyce’s fifth child with his former media adviser Vikki Campion, 33, were widely publicised on Wednesday after rumours of the affair surfaced during the New England by-election in October.

Mr Joyce’s estranged wife, Natalie, said the affair had been going on “for many months and started when she was a paid employee”, and that the “situation is devastating on many fronts”.

“I am deeply saddened by the news that my husband has been having an affair and is now having a child with a former staff member. I understand that this affair has been going on for many months and started when she was a paid employee,”  Ms Joyce was quoted as saying by News Corp.

“This situation is devastating on many fronts. For my girls who are affected by the family breakdown and for me as a wife of 24 years, who placed my own career on hold to support Barnaby through his political life.

“Our family life has had to be shared during Barnaby’s political career and it was with trust that we let campaign and office staff into our homes and into our lives. Naturally we also feel deceived and hurt by the actions of Barnaby and the staff member involved.

“The situation for myself and the girls will be made worse by the fact that this will all be played out in public so at this time, I would ask that the girls and I are given some privacy and time to come to terms with the consequences and take steps to plan our future.”

The statement comes after News Corp published photos of an apparently pregnant Ms Campion on Wednesday.

Mr Joyce’s spokesperson told The New Daily the Minister for Infrastructure and Transport would not comment on his personal life.

He revealed in parliament last year that his 24-year marriage to Ms Joyce had broken down. They have four daughters.

Labor frontbencher Tony Burke said he would not comment on the matter, saying: “It’s something I view as none of my business.

“This ricochets and affects families. There’s a principle here that I’ve always abided by to not engage in anything that hits the private lives of other members of parliament.”

Cabinet minister Dan Tehan agreed.

“My personal view is it’s a private matter, therefore it should be up to the individuals as to what they would like to put into the public domain or not,” he told ABC radio.

Mr Joyce and Ms Campion have reportedly moved in together, and their baby is due in April.

The minister, who has maintained a long-standing position against same-sex marriage, said he believed in the “current definition of marriage” before abstaining from the final parliamentary vote on December 7.

“I don’t come to this debate pretending to be any form of saint, but I do believe in the current definition of marriage, which has stood the test of time,” he said.

“I acknowledge that I’m currently separated, so that’s on the record.

“It is a special relationship between a man and a woman, predominantly for the purpose of bringing children into the world – if you are so lucky, noting that many people aren’t.”

-with AAP