Chris Davies pulled out after other Welsh Tories criticised his selection.

"I will not want to put my wife and family through any more distress," the former Brecon and Radnorshire MP said.

A senior Welsh Conservative source told the BBC the campaign had been "shaky to say the least".

"The candidate selection has been seriously flawed and chaotic," the source added.

Announcing his decision to withdraw from the election, Mr Davies said: "Given the reaction in the media to the idea of me being a candidate, I have decided to pull out of the selection process."

Mr Davies lost a by-election triggered by a recall petition earlier this year.

He admitted two charges of a false expenses claim in March after trying to split the cost of £700 worth of pictures between two office budgets by creating fake invoices, when he could have claimed the amount by other means.

He made an "unreserved apology" and was ordered to complete 50 hours of unpaid work and was fined £1,500.

News of his selection broke on Tuesday night, prompting incredulity from Angela Burns, Welsh Conservative AM for Carmarthen West and South Pembrokeshire.

Claiming Mr Davies had been imposed by the party, she said: "You couldn't make it up."

"It is inexplicable," another Welsh Conservative source said.

Mr Davies had tried and failed to apply to be the general election candidate in Brecon and Radnorshire before the Ynys Mon selection was made.

Lord Davies of Gower, Welsh Conservative chairman, had defended the selection before the candidate quit, saying: "Chris made a mistake and has paid the price. He must now be allowed to move on"

The constituency of Ynys Mon includes the island of Anglesey and the smaller Holy Island.

Labour has selected Mary Roberts for the 12 December poll, while Plaid Cymru has picked Aled ap Dafydd.

The Brexit Party intends to stand Helen Jenner.

Ms Roberts said: "Chris Davies has rightly withdrawn. The Welsh Conservatives are in complete disarray."

Before Mr Davies pulled out, Plaid's candidate said: "By imposing a convicted former MP who was found guilty of a false expenses claim as the candidate for the island shows how little they care about Ynys Mon."

Deputy leader of the Welsh Liberal Democrats Baroness Christine Humphreys said the Conservatives had "demonstrated their utter contempt" for Ynys Mon voters.

The summer by-election cut the Conservative working majority to just one when Jane Dodds overturned Mr Davies's 8,038 majority to beat Conservative Chris Davies by 1,425 votes.