Sterling's steep losses came after the government suffered an unexpected defeat on a separate amendment, which means the United Kingdom will now be required to secure an agreement that allows Britain to have continued participation in the European medicines regulatory framework.
Government defeated an amendment from Tory backbench MPs, which would have kept United Kingdom in a customs union with the EU if it fails to agree a free trade deal.
It was bolstered by the support of four pro-Brexit Labour Party MPs.
Pro-EU lawmakers have tabled a change to the wording of the bill to try to force the government to pursue a customs union with the EU if ministers fail to reach an agreement which establishes "a frictionless free trade area for goods".
Theresa May and DUP leader Arlene Foster visited the Irish border today
This article has been adapted from its original source.
Friends of the former foreign secretary claim he would not have gone ahead with his plan to break his silence so soon after the Commons debates on trade bills this week if the government had lost the crucial vote on the customs union.
Tory MP Gillian Keegan (Chichester) later drew upon the Rolling Stones over Brexit, telling the Commons: "I can't help think that if we'd been offered a deal a few years ago that ended free movement, stopped future payments to the European Union, continued frictionless trade, regained control over our fisheries and farming policies, with no hard border in Northern Ireland, we'd have readily agreed to this - in fact, we'd have bitten their hand off".
Labour Brexiteer Kate Hoey faces a fight for her political future as grassroots members launch a bid to have her suspended and barred from standing for the party again.
In the past 48 hours, the government has narrowly won a series of votes on trade and customs arrangements despite substantial rebellions by pro-European Tories.
She told HuffPost UK: "Over my 29 years in Parliament, I have been censured many times by the CLP".
On Monday night, MPs in Westminster voted in favour of a law designed to create an independent customs policy after Brexit.
If a Brexit deal is blocked in Parliament, May's options would be limited, since she does not want Britain to leave the European Union without a deal, with all of the economic damage that would entail.
"These nonsenses of threatening general elections, and votes of confidence in the prime minister. bring it on, because I shall be the first in the queue to give my vote of full confidence in the prime minister", Soubry said.
"She should do the right thing and trigger a by-election where she can, if she wishes, take her chances against a real Labour candidate".
David Davis, who quit as Brexit secretary just hours before Mr Johnson, did not take up the invitation, instead giving a series of TV interviews to explain his disagreements with the PM but also his personal backing for her.
"If Parliament rejects the Government's Brexit plan, then there would be a "no deal" Brexit".
On Monday (16 July), the other wing of May's Conservative Party - those MPs who want to keep the closest possible ties with the European Union after Brexit - spoke up in the voice of former education minister Justine Greening who called for a second referendum.