Scarborough and Whitby MP Robert Goodwill said he will support Theresa May in tonight's vote of no confidence.
Mr Goodwill said: "Now is not the time to change our leader. We are at a crucial point in our EU negotiations with the European Council at the end of the week.
"A leadership election now would be seen as a self indulgent distraction and would weaken our position.
"Theresa May has shown tremendous determination and tenacity. The whole country should get behind her and I hope my colleagues will do the same."
The news of the leadership contest faced by the Prime Minister comes after Sir Graham Brady, Chairman of the 1922 Committee, announced this morning he received at least 48 letters of no confidence.
The vote will take place tonight between 6pm and 8pm.
As Sir Brady said, votes will be counted “immediately afterwards and an announcement will be made as soon as possible”.