In July, May offered a plan to set Britain out of the single market and create a new "free zone" for agricultural goods and products with the EU based on a customs agreement and a set of common rules. The project, known as the "Shakers Plan" in the name of the summer residence of the British premiership, was immediately met with strong opposition from the Brexit advocates in her own conservative party as they deviated from the outcome of the June 2016 referendum.

Foreign Minister, Boris Johnson, and British Prime Minister, David Davies, resigned in a move that has had a major impact, while European Union leaders have questioned the plan's implementation. "I will not be forced to accept compromises on the Chickers plan proposals that are not in our national interest," May wrote in the Daily Telegraph.

Britain is due to leave the European Union on March 30, 2019, with London and Brussels reaching an agreement by October to arrange the terms of Brexit and establish the rules of their future relationship, so that national parliaments have time to ratify the agreement. In the face of strong opposition from Brexit supporters to her plan, Mai said she preferred not to reach an agreement instead of making further concessions to Brussels. "We will be prepared not to reach any agreement if necessary," she wrote, once again excluded from organizing a second referendum on EU accession. "Asking the question again will be a major betrayal of our democracy and a betrayal of that trust," she wrote.