London (CNN)Downing Street has quashed suggestions that EU citizens will still be able to come to Britain to live and work after Brexit takes effect in March 2019.
A spokesman for Theresa May, the UK Prime Minister, said that the principle of free movement -- one of the guiding pillars of the EU -- would end when the UK leaves.
There had been suggestions that the Chancellor, Philip Hammond, favored a post-Brexit transition period during which immigration would remain broadly the same as before.
"The Prime Minister's position on an implementation period is very clear and well-known," said a spokesman for the Prime Minister in a press briefing.
"Free movement will end in March 2019. We have published proposals on citizens' rights, " he said.
Last week Home Secretary Amber Rudd announced a major analysis of the impact of EU immigration on the British economy.
In her letter to the independent committee carrying out the inquiry, Rudd said made it clear that she also favored a transition period.
"As part of a smooth and orderly transition as we leave the EU, the second phase of our immigration proposals is based on a temporary implementation period to ensure there is no cliff-edge on the UK's departure for employers or individuals," she wrote.
Business leaders have expressed concern that a "cliff-edge" exit from EU immigration arrangements would have a detrimental effect on the UK economy, due to a sudden drop in the arrival of skilled workers from Europe.
British media reported Hammond as having reassured UK business leaders on the issue.
Those seeking a swift clean break for the EU include International Trade Secretary Liam Fox and Immigration Minister Brandon Lewis.
May's spokesman nevertheless indicated that there could be some flexibility.
"Other elements of the post-Brexit immigration system will be brought forward in due course," he said. "It would be wrong to speculate on what these might look like or to suggest that free movement will continue as it is now."
The spokesman said most of May's positions on the immigration aspects of leaving the EU were laid down in a speech last January in Lancaster House, London.
"She said "It's in no-one's interest for there to be a cliff edge for business or a threat to stability, as we change from our existing relationship to a new partnership with the EU", the spokesman said, directly quoting from the PMs speech.
"She also said: "By this, I do not mean that we will seek some form of unlimited transitional status, in which we find ourselves stuck forever in some kind of permanent political purgatory. That would not be good for Britain, but nor do I believe it would be good for the EU". This remains the position of the Prime Minister and of the government."
There are more than three million EU nationals living in the UK, while some 1.2 million UK citizens live in other EU states.
Both the British government and the EU have said that finding a reciprocal deal for their citizens remains a priority in the Brexit negotiations.