A spokesperson for Theresa May has said free movement of EU citizens will end as soon as Britain leaves the bloc in March 2019.
The news torpedoes earlier suggestions that there might be a transitional phase after Brexit, with free movement extended.
May is currently on holiday, but was moved to clarify the situation after days of squabbling among her Cabinet on the issue.
Chancellor Philip Hammond had suggested that free movement could go on for up to three years after the conclusion of the Brexit negotiation process.
Hammond had also said there was "broad consensus" in the cabinet over the idea of a transitional agreement, however this suggestion was rejected yesterday (July 30) by trade secretary Liam Fox.
Meanwhile, Home Secretary Amber Rudd suggested migration from the European Union might continue with a registration system.
The Prime Minister's office maintained her position on free movement was set out in her speech at Lancaster House earlier this year.
The date of March 2019 is exactly two years from the time Article 50 was formally triggered in March 2017.