"I think being part of a 500 million population trading block is significant for us. I think one of the issues is that a lot of people will invest here in the UK because it is the UK in Europe. And I think if we were not in Europe, I think there would be firms and companies, who would be looking to say, do they need actually to develop a mainland Europe presence rather than a UK presence," May said at a private Goldman Sachs speech, leaked to The Guardian.
She also mentioned that there would be certain security benefits for the United Kingdom if it opted to remain in the European Union, namely the information-sharing among intelligence and police agencies, according to the newspaper.
In contrast, addressing the Conservative party's conference in Birmingham on October 5, May prioritized reducing migration over being part of the single European market.
On June 23, the United Kingdom held a referendum to determine whether or not the country should leave the 28-nation bloc. According to the final results, 51.9 percent of voters, or 17.4 million people, decided to support Brexit, while about 16.1 million opposed it.
On October 2, May said that the country would trigger Article 50 of the EU Lisbon Treaty by the end of March 2017 to start the official procedures to cease its EU membership.