Norman Smurthwaite has confirmed he is standing down as the chairman of Port Vale with immediate effect.
Smurthwaite helped take the club out of administration, along with previous chairman Paul Wildes, in November 2012.
He took over as chair and sole owner of the club when Wildes resigned six months later.
But in a statement released this morning he says that the "thinking outside the box" decision he made last summer to bring in Bruno Ribeiro "clearly seriously damaged our club, resulting in Sunday’s relegation".
Norman - known to many fans as 'Smurf' - says he also regrets losing Micky Adams, who was "more than just a manager", and says after his departure he "became vulnerable without his structured management of the football department."
The statement continues: "Being focused in trying to stabilise the club I ignored and took for granted the most important asset the football club has, and that is you the supporters. When I really understood that, I think for some of you that was unfortunately too late.
"I deeply regret the actions and appointments I made during the closed season and would like to apologise sincerely to all supporters, Port Vale staff and the wider Burslem community for the impact of my decisions last summer."
He says that where in his business life he has suffered setbacks he has brushed himself off and got on with things, but says "due to the environment of the last few months, I do not feel that is now possible."
Norman has confirmed the club is still for sale, but he "will endeavour to ensure that the right party purchase the club."
Vale Chief Executive Colin Garlick will take over the running of the club until a takeover is completed.
Stating that he will no longer be attending any matches, Norman said: "All that I ask is that you, the supporters, please put any differences that you may have behind you and try to fully support your club as it will need you now more than ever."