May's government is divided between Brexit-backing ministers such as Foreign Secretary Boris Johnson who support a clean break with the European Union, and those such as Treasury chief Philip Hammond who want to keep closely aligned to the bloc, Britain's biggest trading partner.
So just hours after the concession, (or non-concession) very, very dark mutterings began from those who had been persuaded by what they thought was a promise.
Some lawmakers tried to shout him down and accused the government of wanting too much power.
The government concession is all the more remarkable because of the strength of opposition to the original amendment from ministers.
The vote on Tuesday is the first of two days of debate that will test May's authority and her plans for leaving the EU.
The frontpages of Leave-backing British newspapers said accepting the amendments would betray the 52% who backed Brexit in the seismic 2016 referendum.
British women march to celebrate suffragettes
Women marched in the colours of the suffragette movement, buying out purple and green tassels in a craft shop in London. They added: " Processions celebrates the fight for suffrage and expresses what it means to be a woman today".
"The prime minister said that the votes were important in terms of the message they send to Brussels", May's spokesman said she told her cabinet team of ministers.
The government says the changes would weaken Britain's negotiating position and is seeking to reverse them in the Commons.
The Brexit Secretary warned that the UK's entire approach to negotiations with the EU is at risk of being undermined by amendments to its flagship EU Withdrawal bill.
Dr Lee said his main objection to Government policy was over the "wish to limit Parliament's role in contributing to the final outcome" and signalled he would rebel on the issue in the Commons later.
In the tense atmosphere where it was not clear which way the vote would go, the government secured its victory only after offering concessions to one of the leaders of a group of Conservative lawmakers who were threatening to vote against May.
The parts of his amendment which he expects to be taken forward by ministers provide a mechanism by which Parliament has to be consulted by the end of November in the event of no deal or if a proposed agreement is rejected, he said. The strength of this commitment is yet to be seen in writing - and the Brexit department is still insisting it has not given up control of the negotiations - but the anti-Brexit rebels showed they have the numbers to force a defeat should the government renege on its pledge.
Sen. Graham: "China is trying to play President Trump though North Korea"
That should be something that is seen as naive and seen as something that really serious people shouldn't even be discussing". Rand Paul said during a televised interview.
"Time will tell as to whether this is just another attempt to buy off the rebels or a real attempt at consensus".
Phillip Lee, Member of Parliament for Bracknell, stood down from his position as Justice Minister because he "couldn't support how our country's current exit from the European Union looks set to be delivered".
This change sought to give greater powers to the "sifting committee", which would be established to decide whether recommendations proposed by ministers to amend retained European Union law after Brexit would require a Commons vote.
The result left Prime Minister Theresa May to fight another day as she tries to take Britain out of the bloc while retaining support from pro-EU and pro-Brexit wings of her Conservative Party.
Theresa May saw off a revolt from the pro-European wing of her fractured party, averting what could have been a major political crisis.
What is the EU Withdrawal Bill?
Hurricane forecasters tracking system in Caribbean
A system has to have a closed center of circulation and winds of at least 39 miles per hour to be considered a tropical storm and get a name.