They will take over from July 27, with Nigel Planer and Verity Rushworth continuing as Wilbur Turnblad and Penny Pingleton respectively.
Newcomer Hart takes over as his daughter Tracy, in her first job since graduating from the Guildford School of Acting. Tamne was recently in the West End production of Wicked at the Apollo Victoria.
Conley, who began his career as a holiday camp entertainer for British company Pontin's and then started his television career as a warm-up man for Terry Wogan, Noel Edmonds and Kenny Everett, has appeared on TV in his own series, "Brian Conley: This Way Up" and "The Brian Conley Show," as well as in the sitcom "Time After Time" (awarded the British Comedy Award for Best ITV sitcom), and playing Doug "Dynamo" Digby in "The Gimleys."
On stage he was most recently seen onstage in 2008 in Chichester Festival Theatre's production of The Music Man. Other West End roles include taking over in Me and My Girl at the Adelphi Theatre, originating the title role in Jolson at the Victoria Palace Theatre, appearing in David Farr's Elton John's Glasses at the Queen's Theatre, and starring as Caracticus Potts in Chitty Chitty Bang Bang! at the London Palladium, subsequently recreating the role on national tour.
Among his awards, he has won The National Television Award for Most Popular Comedy Performer, Show Business Personality of the Year and Most Popular Performer in the 2004 Manchester Evening News Theatre Awards. In a press statement, Conley commented on working with his new stage husband Nigel Planer, "Nigel is one of my heroes and it's a professional highlight for me to kiss him not just once but twice a night (four times on Thursdays and Saturdays). I am looking forward to the role hugely but I'm not looking forward to the stubble rash. I've insisted that he shaves before every performance and moisturizes. I've also been practicing in my reinforced heels around the house, which upset the neighbors because I left the curtains open and usually I only dress up on a Wednesday. My only worry is that I now look like my mother!"
To book tickets, contact the box office on 0207 379 5399 or visit www.hairspraythemusical.com for further information.