Conservative MP Caroline Spelman has backed Theresa May's Brexit deal - and said some of its critics decided to oppose it before they had any idea what it said.
The Meriden MP said: "This is the time for cool heads and rational thinking, not hot headed emotion."
And Mrs Spelman said she backed Mrs May - but was "dismayed by the opposition she faced in Parliament from all sides."
Mrs Spelman said she backed the proposed deal agreed by the Cabinet, saying: "I am full of admiration for Mrs May who calmly and patiently explained the detail to our Parliament but it was as if many MPs had, on the basis of hysterical press speculation, pre-decided that the deal equated to 'treachery'."
It had always been clear that the UK would need to make compromises in order to secure a deal, she said.
She said "A reality check is required. No deal would be a disaster for the West Midlands which exports more than any other region to the EU.
"Why would business produce goods here for its principal market if barriers and tariffs are to be put in its way by no deal?
"No deal would put at risk the recovery of manufacturing which has given a whole generation of young people a great start in well paid, skilled jobs.
"This deal gives us back control over our borders, our law making and our money so why reject it?
"We will not have the same degree of influence over the club we are leaving but, just like a divorce there is always a price
"For the fresh start the country voted for at the referendum this is the best deal on offer and the EU has said it will not improve on it."
Theresa May was thrown a lifeline when Environment Secretary Michael Gove said he intended to remain in the Cabinet.
It followed the resignations of Brexit Secretary Dominic Raab and Work and Pensions Secretary Esther McVey.
But Mrs May faces mounting pressure from within Tory ranks as further MPs called for her to be ousted.
Speaking outside his departmental office, Environment Secretary Mr Gove was asked if he had confidence in the Prime Minister and replied: "I absolutely do."
He added: "I am looking forward to continuing to work with all colleagues in Government and in Parliament to get the best future for Britain."
Sources indicated that the number of letters submitted to Sir Graham Brady, the chair of the backbench 1922 Committee, may now be nearing the 48 needed to trigger a no confidence vote in Mrs May.
Former Brexit minister Steve Baker said he had been speaking to colleagues and his count was "a little over 48" with another dozen "probable" - although he acknowledged this may be inaccurate as only Sir Graham knew the true figure.