Paul Hart took over as manager of Rushden & Diamonds, following the departure of Barry Hunter. After an average start to the season, Diamonds embarked on an eight match winless run, leading to Hart leaving the club in October by mutual consent. Hart joined Premier League club Portsmouth as Director of Youth Operations in 2007. He was asked to take over as caretaker manager, initially for one game only following the sacking of Tony Adams on 9 February 2009. Shortly afterwards, Hart brought Brian Kidd in as his assistant. He won his first game in charge 2–0 at home to Manchester City
Mark Hart backing vocals for their album, "Free as a Bird", which was issued in October 1987. Hart also shared the same manager as pop-rockers Crowded House, who suggested he fill in for their keyboardist Eddie Rayner with session work for the band after they experienced difficulties working together. In 1991 Hart contributed to "Woodface" as a session musician, later joining the band as a touring member when Tim Finn left. In 1993 Hart was credited as a full member for "Together Alone". He stayed with the band after founding drummer Paul Hester left, and is seen along with the group's founders