Broxtowe's MP Anna Soubry said in a passionate letter to constituents that she is "appalled and embarrassed to be a Conservative MP" after her party called a vote of no confidence in Theresa May.
At least 48 MPs triggered the vote in the Prime Minister, which saw all 317 Tories vote on whether or not they had confidence in Mrs May moving forward with Brexit.
Mrs May won that vote by 200 to 117 votes, meaning another challenge cannot be made for 12 months - securing her position as Prime Minister for now.
Due to the divisions, Broxtowe MP Anna Soubry sent a passioned letter to her constituents suggesting that Conservative infighting is "damaging the country".
She said: "Today I am ashamed to call myself a Conservative given the irresponsible actions of a small group of Conservative MPs who have called a vote of no confidence in the Prime Minister, Theresa May.
"The last thing our country needs or wants is a change in Prime Minister. I do believe we need a change in direction on Brexit; I believe Theresa May will have no other option than to return the matter and her deal to the people, but removing her from office at this most critical of times, is most certainly not in the national interest.
"The small group of MPs who have put in 48 letters of no confidence represent the right wing of the Conservative Party who have blighted the party for decades.
"Unfortunately, like too many other Prime Ministers before her, Theresa has overly indulged them instead of seeing them off - I hope she will this evening.
"On Monday I was embarrassed to call myself a Member of Parliament after the Government decided to pull the vote on the Prime Minister's Brexit Withdrawal Agreement.
"Whilst appreciating the scale of the vote against the Agreement would be very difficult for Theresa May, after days of debate and over a hundred speeches, it should have taken place last night.
"The Withdrawal Agreement must come back to the Commons and be voted on before we rise for the Christmas recess next week.
"This most important of matters since the Second World War cannot be delayed, especially with just over three months to go before we are due to leave the European Union.
"Finally, whilst apologising for the current state of politics in our country and the great uncertainty caused by this crisis over Brexit, please be assured that I and the majority of my colleagues, will put the interests of the country before narrow ideology and party political allegiance."