Following the annual meeting in February Tremain, a son of All Blacks and Magpies legend, the late Kel Tremain, Randell and fellow board members Kevin Atkinson and Dan Druzianic raised issues about the organisation's leadership and board succession.
"The board has reached an impasse as to future direction. My own experience shows that we need an opportunity for new people to enter and hence my decision to vacate to allow that to happen. There needs to be new fresh faces that can revitalise the organisation and rugby across the region," Tremain said.
"There has been a lot of focus on the Magpies, and while this is very important, so is club and school rugby. The union hasn't engaged as well as it could with the clubs, and that's the lifeblood of grassroots rugby. A strong club scene leads to a stronger and more balanced provincial rugby union," he added.
Randell said he believed the union had not moved too far forward since he joined in 2012 and new blood was needed.
"The face of rugby has changed in the modern era and we have to either adapt or get left behind. The makeup of the board needs to be seriously looked at and I'm not sure that it's a relevant make-up of those that participate and support the sport."
"I am passionate about Hawke's Bay rugby but I feel, under the current structure, I am unable to serve in the best interests of the union," Randell added.
Tremain said all high performing organisations have in place a strong board succession plan, including chairman with recruitment at the forefront. While Tremain didn't want to comment further on his release, it is understood he stood against union chairman Brendan Mahony for the role at last month's board meeting.
When the vote ended in a 4-all draw Tremain withdrew his nomination with the proviso a succession plan was an item on the agenda for yesterday's meeting. When he was told it wasn't on the agenda he decided to resign.
While reliable sources suggest two other board members could also resign by the end of this week Mahony said, as far as he was aware, there wouldn't be any more.
He pointed out Randell and Tremain could have stayed on the board and worked constructively but they both had different ideas in life.
"Our constitution allows us to call for nominations from the clubs. We will have a special general meeting where I am sure two good replacements will be available to come forward."
Hastings Rugby and Sports club delegate Jack Sanders said he was surprised by the pair's resignations but didn't want to comment further.
Delegate for the Napier Old Boys Marist club which nominated Tremain, Terry Gittings, said he was surprised the pair mentioned the union hasn't engaged as well as it could with clubs.
"We've had three new rugby development officers appointed during the past 12 months and a women's rugby development officer. One of those officers, Jarvy Aoake, goes to junior rugby board meetings and Gary Macdonald does a tremendous job as the union's club development officer.
"I haven't had an email or text from Simon or Taine during the last 12 months to sit down with them and discuss club rugby," Gittings added.
