British Prime Minister Theresa May on Thursday dismissed Brussel's insistence that EU nationals arriving in the UK during the two-year Brexit transition period should have the same residency rights as those already living in the country. 

"People who had come to the UK when we were a member of the EU had set up certain expectations — they made a life choice and set up certain expectations," May told reporters during her visit to China.

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"I'm clear there's a difference between those people who came prior to us leaving and those who will come when they know the UK is no longer a member of the EU," May added.

Curbing immigration was one of the key reasons Britons voted to leave the EU in 2016. Many of the hardline Brexiters in May's Conservative Party have voiced concerns that her government is on course for a so-called "soft Brexit," which they fear would lead to little change in the country's current relationship with Brussels.

May sought to dismiss those concerns Thursday, saying: "They did not vote for nothing to change when we come out of the EU. What we're doing now is doing the job that the British people asked the government to do which is to deliver on Brexit."

Citizens' rights a major negotiation point

During the first phase of Brexit negotiations, both sides agreed to a two-year transitional period after the UK formally leaves the bloc in March 2019. 

Brussels believed the UK had accepted its offer of continued access to the single market during that time, in exchange for a guarantee on full residency rights.

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May's remarks therefore provoked a harsh response in Brussels, where officials remain adamant there can be no compromise on the four freedoms during the transition.

Guy Verhofstadt, the European parliament's chief Brexit negotiator, told the UK's Guardian newspaper that the rights of EU citizens during the transition were "not negotiable."

"We will not accept that there are two sets of rights for EU citizens," he said.  "For the transition to work, it must mean a continuation of the existing acquis with no exceptions."

Philippe Lamberts, a European Brexit official, warned of a looming clash between the two sides. "Citizens' rights will be a negotiation point and we want to stand firm on this that new provisions only enter into force after the end of the transition period," he said.

dm/kms (Reuters, AP, dpa)