The sacking of an up-and-coming senator helped spark a rebellion to unseat Opposition leader Jeanne Atherden, a party insider said yesterday.

The One Bermuda Alliance member said that the firing of Nick Kempe, who resigned as party chairman after Ms Atherden axed him from the Senate only days after she took over as leader, had dented her credibility.

The source said: “Things went off the rails for her immediately when she got rid of Mr Kempe.

“He had done a lot of work, and the rationale didn’t hold up well. He was blindsided by that and the party lost a lot of momentum.”

The source was speaking after Ms Atherden, who was appointed last November and leader for little more than 300 days, resigned on Thursday night after a behind-the-scenes meeting of the parliamentary party passed a vote of no confidence in her leadership.

Eight of the OBA’s 11 MPs backed the motion. Ms Atherden, Michael Dunkley, the shadow national security minister, and Trevor Moniz, the shadow Attorney-General, were not at the meeting.

Craig Cannonier, a former OBA premier, is thought to be the front-runner to replace Ms Atherden and party executives are expected to discuss next steps on Monday.

The insider said Mr Cannonier attracted some support when he ran for the leadership of the party last year, but that Ms Atherden had worked hard to secure the post.

The party source added: “There is not a long line of people who want to take on what is a pretty thankless job.”

Others connected to the party said the way Ms Atherden had been dumped was wrong.

Mr Dunkley, a former premier, said he was told about the Wednesday meeting on Monday night — but not the subject.

He was already scheduled to be overseas and could not attend.

Mr Dunkley said: “When I asked what the agenda was I was told it was to prepare for the November session.

“I was disappointed that the meeting was called with such short notice and I was going to be off the island.”

He added: “While politicians are free to engage the rules and responsibilities that they have, I do not believe that the matter was handled in an appropriate, responsible, and respectful way.”

Another member of the party faithful said he was not surprised that the leadership challenge had taken place.

But he added he was disappointed about the way it was handled, given the hard work Ms Atherden had put in.

The member said it was possible some may have thought Ms Atherden was not aggressive enough as leader.

But he added that some of those involved in the “coup” had not been active in the party during her time as leader.

The member added: “It’s hard when you have members of your team who are not participating or supporting the leader.”

Another party member said people who were upset about Ms Atherden’s leadership style had failed to make that clear to her.

Ms Atherden announced her resignation in a letter yesterday after news broke about the motion of no confidence.

The letter said: “We cannot, especially now, step back. We must all continue our efforts to unite the party and must all work towards common identified goals and not just sit back and leave it up to the faithful few or wait for things to fail.

“It is by harnessing our individual strengths that we make the party stronger.”

She added: “We must continue to develop an OBA that projects fairness and integrity, an OBA which promotes social and economic equality, an OBA which is inclusive and ensures the voices of women and our younger members are heard.”

Ms Atherden said that under the OBA constitution an election would be required to pick a new party leader.

She added: “This is an important election for the OBA. It will give members the opportunity to get behind a leader who can best strengthen and unite the party and lead us according to our values and principles to represent all of Bermuda as an opposition party and government-in-waiting.

“This new leader will prepare us for and lead us into the next election.”

Mr Cannonier led the party to victory at the polls in 2012, but quit less than two years later after the “Jetgate” row over a trip he took in a private jet to the United States.

Mr Cannonier could be sworn in as Opposition leader at Government House on Monday.

But he would need to go through a separate process to become party leader.

Leah Scott, the OBA deputy leader, is to act as leader until the role is filled through the party’s election process.

John Rankin, the Governor, confirmed that a swearing-in ceremony for a new Opposition leader would happen on Monday.

In a message to members yesterday, Justin Mathias, the OBA chairman, said he had accepted Ms Atherden’s resignation. He added: “I would like to take this time to thank the leader for her work in the post and wish her the best in her future endeavours.

“Working closely with her as a member of the executive, I’m sure she will continue to represent her constituents’ concerns inside the House and out.”

The OBA’s constitution rules that, after a vote of no confidence has been called by MPs, party members must elect a new party leader.

Mr Mathias said an executive meeting was planned for Monday, when the nomination deadline would be outlined as well as the “rules of the leadership contest”, and members will be informed.

Owen Darrell, the chairman of the ruling Progressive Labour Party, thanked Ms Atherden for her service to the island as Opposition leader.

He added: “As the members of the OBA continue to sort out their affairs, we in the PLP will stay focused on the work we were elected to complete.”