Policy and Reform Minister Chris Robertshaw has quit after less than a year in the post.
He'll remain a member of the House of Keys but says he's unlikely to stand in the next election.
The ministerial role was created alongside the Cabinet Office last April as part of a bid to streamline the government. Mr Robertshaw says he's resigned because his colleagues could not accept his plans to change what he calls a 'too top heavy, too departmentalised' and 'dysfunctional' government, adding: 'You really only have to bash your head against a brick wall so many times before you knock yourself into unconsciousness.'
He's handed a letter of resignation to the Governor's office but says he has not had the opportunity to speak to Chief Minister Allan Bell.
Watch the full MTTV interview
Got a story? Contact Joanne on 340000 or email newsdesk@manx.net
twitter @jonewsiom