LEEDS West Labor MP Rachel Reeves said Tory Remainers must "stick to their weapons" ahead of an important vote in Parliament on the Prime Minister's Brexit agreement.
Ms. Reeves, chairman of the Business, Energy and Industry Strategy Committee, has warned of the choice between the Checkers Theresa May plan and the Brexit no-deal is "wrong choice."
He said work and investment "will flow out of this country" if Britain does not remain on a single market and customs union.
His comments came when Mrs May could potentially face a vote in Commons about the Brexit agreement he completed with the European Union in the coming weeks.
Speaking to the Press Association, Ms. Reeves said: "Well, I hope that those in the Conservative Party like Anna Soubry remain on their weapons today because there are too many opportunities in the past where … they have rolled in the last minute. I think it is unfortunate that Dominic Grieve is not ultimately returning his own amendments because it will make it easier to change the Brexit agreement if he is stuck with it, so the procedure for getting a better agreement or rejecting the Government agreement will be more difficult than it should if the weapon.
"And that's the concern that I think is really happening, that until now the ERG (European Research Group) has never backed down, but those who have the remaining sympathy still exist.
"There are actually more people with that sympathy, with more sympathy left in Parliament or gentle Brexit sympathies, than for the hard Brexites, only the hard Brexites are more violent."
The red line set by Mrs May at the start after triggering Article 50, he said, had "really hampered the process" and made it "far more difficult to reach a compromise".
Ms Reeves said: "I think the Prime Minister really wants to get an agreement.
"He doesn't want to be the Prime Minister who takes us to the brink and I think he also thinks it's his job to do that."
He added: "I will not choose the Checkers type agreement … I think it is a wrong choice to say the choice is between Checkers and no agreement.
"I hope the PM can make an agreement with his European partners, but unless it meets some of the red lines my party has set and what I'm talking about, I won't be able to support it.
"Because unless we remain in a single market and customs union, I think work and investment will flow out of this country and I cannot with a good conscience for an agreement that I know will make my constituents and the state worse off. "
Ms Reeves said there were other alternatives, including extending the negotiation period or returning to the country, adding: "I think what is in front of us today in terms of Checkers or no agreement is the result that most people in the country will refuse and so I think people must be given the opportunity to express their opinions about the Brexit agreement that will change the direction of this country at least for generations to come. "
He also voiced concern about how the EU referendum was opposed.
Ms Reeves said: "We have strict rules in this country, and rightly so, around campaign funds and if they are not adhered to and if the referendum is won fraudulently, it does not question whether the referendum itself is legal."
The Brexit no-deal, Ms Reeves warned, would be an "absolute disaster", adding that the BEIS committee took evidence from manufacturing businesses that voiced "big concerns" about customs inspection and separation from the EU regulatory framework, especially in the automotive sector.
He said businesses were "very reluctant" to talk about the risk of Brexit for "understandable reasons", with some not wanting to "sour" relations with the Government, others not wanting to send a signal to shareholders that there was a big risk ahead, plus consideration over do not want to create uncertainty for their workforce.
The Labor MP said: "They are not reckless, they only talk when they think that there is an existential risk with the way they run their business and I hope the business will talk more and will speak early.
"My business experience is that they only talk about political issues when they really think there is no alternative to doing so."
In Labor's position, Ms Reeves said she was "one of the people who pushed our party's leadership into a more pro-People Vote position", adding the Labor Union referendum campaign "could be stronger and I think it could be better led from the top of the organization. "