A Welsh Conservative MP has written an open letter to the Prime Minister, calling for her to step down as leader.
Jamie Wallis, who represents Bridgend, published the letter on his Twitter - saying "enough is enough".
In the letter Mr Wallis asks Liz Truss to step down, stating it would be the "right thing to do" as she has lost "the confidence of the country" and her party.
It comes as two other MPs within her own party have also publicly called her leadership into question due to her handling of recent events.
Jamie Wallis claims that Ms Truss has made "very basic and avoidable errors" that "undermine Britain's credibility as a trustworthy, responsible leading economy".
He said the damage can only be undone if the party has a new leader.
He points to the choices she made on ministerial appointments - particularly her decision to select an English MP as Secretary of State for Wales - the way in which her MPs are managed by senior staff and her handling of the press all as reasons she should step aside.
Meanwhile, the leader of the Welsh Conservatives voiced his support for Truss on Monday morning and called for the party to end its "internal civil war".
He told BBC Radio Wales, "The Conservative party now needs to come to its senses, cease this internal civil war that's going on, and rise to the challenge and the privilege that this country has given it of being in government in Westminster and delivering for people across this country."
Mr Wallis, who came out as transgender earlier this year, added that "watching senior colleagues exploit the issue of transgender rights and weaponise it to score cheap political points" during the leadership contest was "extremely unpleasant".
He writes to the Prime Minister that she "chose not to challenge this behaviour" and has "chosen to have those same colleagues sit alongside" her in her government.
He ends the letter with: "I ask you to stand down as Prime Minister as I believe you no longer hold the confidence of the country or the parliamentary party.
"It is the right thing to do to ensure the stability, security and prosperity of the people to whom we owe everything."
Wallis joins the MP for Reigate, Surrey, Crispin Blunt and North West Leicestershire MP, Andrew Bridgen, in putting pressure on their leader to step down.
On Channel 4’s Andrew Neil Show, Mr Blunt said, "it’s now a question as to how the succession is managed" while Mr Bridgen told the Telegraph newspaper: “We cannot carry on like this."
Ms Truss' premiership has been marred by turmoil within the financial markets and u-turns on plans set out in the former Chancellor, Kwasi Kwarteng's, mini-budget.
The First Minister called for a general election to be held after Mr Kwarteng was sacked.
Speaking to ITV News following Mr Kwarteng's departure from the role, Mark Drakeford said "an enormous amount of damage has been done to the credibility of the new UK Government" and a general election was "absolutely the right thing".
The new Chancellor, Jeremy Hunt, will outline his spending and tax plan on Monday (17 October) morning, bringing forward measures from the medium-term fiscal plan. This will be seen as a bid to reassure the financial markets.