Representative Will Quince has resigned as Secretary of Defense Secretary Gavin Williamson's parliamentary secretary, saying he "can not endorse" the Prime Minister's resignation.
The Conservative MP for Colchester's announcement is the latest blow to Theresa May's Brexit deal since she announced her plan.
In the Telegraph, Mr. Quince wrote: "I wanted to support this resignation agreement, and I want to continue to support it. However, if the attack does not have an end date or a one-sided exit mechanism, I can not support it. I resigned from the government as a Parliamentary Private Secretary.
"I urge the Prime Minister to return to the European Union and find another way to make this resignation treaty something we can all support."
The 35-year-old is the last in a series of politicians who have revealed their Brexit Plan since the Prime Minister.
Ms. May warned she could be forced to serve as leader if she continued her Brexit deal if she was rejected by parliament.
Euro-skeptic and former Tory leader Iain Duncan Smith warned against Ms. May and her cabinet, who would choose to slow it down if MEPs tabled their Brexit plan in parliament on Tuesday