The BBC's Caroline Evans looks back at the highs and lows of Rod Richard's colouful career

In a statement he said he felt he was left with no choice after being "undermined" by party members.

"I asked the Tory group to endorse my appointment of David Davies," he said.

"They did not do so. I therefore feel my authority as leader has been undermined and I have no alternative but to resign.

The BBC's Derek Evans: "This has been embarrassing for the party"

"I will continue to work hard for all of my constituents in the Assembly."

His announcement followed the news that Nick Bourne has been made the new acting leader of the Tory members of the National Assembly for Wales.

The decision was taken after Tory members rejected Rod Richards' choice - 29-year-old Monmouth AM David Davies.

They said they believed Mr Davies was "too inexperienced".

It was over the weekend that Mr Richards "stepped aside" from the leadership following allegations of assault made against him by a 22-year-old woman.

Assault 'fabrication'

Married with three children, he is charged with causing grievous bodily harm to Cassandra Melvin on 27 July, at Kew in west London.

Former rival Professor Nick Bourne elected new acting leader

But he described the assault charge as a "complete fabrication", and vowed to fight it.

The appointment of Mr Bourne as acting leader was made at a Conservative party meeting in Cardiff, just hours before Mr Richards' resignation.

Mr Richards spent only 10 minutes at the gathering, emerging to say he had once again asked AMs to back Mr Davies as deputy leader. He had, he said, left the decision with them.

But it was to be a decision that would lead to his resignation.

Shortly after members issued a statement saying that Nick Bourne - one of the Tories' regional list members of the Assembly - had been appointed the new acting leader.

Mr Bourne was a one-time arch rival of Mr Richards, having been defeated by him in a ballot of Welsh Tory members to elect the leader of the party in Wales.

Rejection of no confidence

The BBC's Simon Morris: "Nick Bourne takes over a party damaged and traumatised by events of the last six days."

Mr Davies has denied that the decision was proof that his Conservative colleagues had no confidence in his abilities as a leader.

He has also vowed to work with the new leadership, denying he has "snuggled up" to any particular faction.

"I will work with anyone to the best of my ability, The important thing is the party is well led," said Mr Davies.

He added: "I hope that Rod Richards will clear his name. When that has happened, I do not know what the situation will be."

Jonathan Evans, Welsh Tory MEP, said Mr Richards now had to concentrate on matters away from the political arena.

"He faces a serious situation and the whole focus has to relate to those legal proceedings," he said.