When the U.K. voted in 2016 to leave the European Union, supporters framed it as a fresh start — a win for sovereignty, the potential to save money and maintain greater control over immigration. After nearly four years of scuttled deals, missed deadlines and parliamentary shake-ups, the U.K. legally exits the EU on Jan. 31.
The U.K. government now has until Dec. 31, 2020 to renegotiate trade deals with EU member states and global partners, during which time it will remain under existing EU regulations.
While the temporary continuity gives businesses in the U.K. and EU some breathing room, they have long voiced concern about the potential for supply chain disruptions. Many have been stocking up on goods and shifting operations to mainland Europe in preparation for slowdowns at key U.K. ports and customs facilities should politicians' best-laid plans fail.
Here's a look back at how it all unfolded, and check back in the future as we chart the impact on supply chains going forward.
Brexit uncertainty: A timeline
January 31, 2020
Brexit becomes official
The U.K. will withdraw from the European Union at 11pm local time on Jan. 31. It will have until Dec. 31, 2020 to renegotiate individual trade and regulatory agreements with member states before formally exiting the EU and setting out on its own.
January 10, 2010
The Brexit bill now goes to the House of Lords. If approved, the U.K.'s withdrawal from the EU could formally become law by the Jan. 31 deadline.
October 21, 2019
The move forces Johnson to ask the EU for an extension until Jan. 31, 2020.
October 17, 2019
The deal removed the "backstop" found in Theresa May's deal that would have kept the UK in the EU's customs union.
April 10, 2019
"Please do not waste this time," said European Council President Donald Tusk.
April 3, 2019
"I am offering to sit down with the Leader of the Opposition and to try to agree on a plan — that we would both stick to — to ensure that we leave the European Union and that we do so with a deal," May said.
April 1, 2019
The customs union was the closest to gaining a majority, but still failed 276-273.
March 28, 2019
The votes came after Prime Minister Theresa May said she planned to step down if her Brexit agreement is passed and the U.K. leaves the EU.
March 25, 2019
"I must confess that I am skeptical about such a process of indicative votes," May told Parliament before the vote to shift control passed.
March 21, 2019
The EU agreed to move the deadline to May 22 if Prime Minister Theresa May could persuade Parliament to pass her withdrawal agreement.
March 18, 2019
The speaker of the House of Commons in the British Parliament, John Bercow, said Prime Minister Theresa May cannot bring her Brexit legislation up for a vote unless it is "substantially" different than the previous versions that failed.
March 14, 2019
This still had to be brought to the EU for approval.
March 12, 2019
Parliament rejected Prime Minister Theresa May's Brexit proposal for the second time with a vote of 391 to 242.
March 6, 2019
Toyota and BMW said this scenario could make U.K. business untenable.
Feb. 27, 2019
Boeing began shifting spare airplane parts around its distribution centers in the U.K. and around the world in preparation for a potential no-deal Brexit.
Feb. 22, 2019
The British Retail Consortium said a no-deal Brexit could result in tariff hikes of up to 45% on "some everyday food items."
Feb. 5, 2019
Honda plans to close its plant in Swindon, England, at the end of its current production cycle, which ends in 2021.
Feb. 4, 2019
The government sent letters to 145,000 businesses currently doing business with the EU to let them know about the new rules and what they need to do to prepare.
Jan. 23, 2019
Amazon advised its U.K.-based sellers to build up inventory and prepare for a slowdown or shutdown of cross-border shipping in the event of a hard Brexit.
Jan. 3, 2019
The U.K. awarded three freight contracts worth 108 million British pounds ($135.9 million) to help ease congestion on the English Channel.
Oct. 31, 2018
The International Air Transport Association warned Brexit — "hard" or not — could pose significant risks to air-reliant supply chains in the U.K.
Oct. 24, 2018
The British automaker currently brings in several parts from the Port of Dover, which is just 25 miles from the Port of Calais in France.
July 9, 2018
The British Retail Consortium estimated 12,500 small businesses would face a high risk of folding if negotiators don't reach a deal.
July 5, 2018
Port of Rotterdam Authority CEO Allard Castelein said he feared the port could lose half of its throughput from the U.K. if Brexit negotiations result in "no deal" between the two parties.
March 12, 2018
The European Sea Ports Organization called on Brexit negotiators to make maritime transport and the flow of goods between ports a priority in their talks.
Nov. 7, 2017
The number of non-British European companies expecting to relocate at least part of their supply chains out of the U.K. rose to 63% from 44% when surveyed in May.
June 24, 2016
The decision led the pound to plummet as "leave" supporters celebrated, The Guardian reported.