Greg Barker married Celeste Harrison in 1992 but they separated in 2006 and then divorced. The Daily Mirror revealed that he had left his wife and children for a man.  The Sun reported that the man was an interior designer employed to oversee renovations on the Barkers' Peasmarsh family home. The Conservative Party's Equalities Manifesto in 2010 listed him as one of three openly gay front-bench Conserviative MPs.
He was included under "Lifetime Achievement Award" in The Independent on Sunday’s Pink List 2011.
He did not stand for re-election in the 2015 general election.
- http://www.mirror.co.uk/news/tm_headline=it-s-such-a-shock---but-men-think-they-can-get-away-with-it-these-days---mother-in-law-georgina-&method=full&objectid=17992356&siteid=94762-name_page.html Daily Mirror, 26 October 2006, "Exclusive: Top Tory dumps wife for man"
- http://www.thesun.co.uk/article/0,,2-2006490561,00.html Tom Reilly in The Sun, 26 October 2006. "Gay fling for Tory MP"