British Prime Minister Theresa May attends a press conference at the end of a two-day EU Summit in Brussels, Belgium, June 23, 2017. (Xinhua/Ye Pingfan)

LONDON, June 26 (Xinhua) -- British Prime Minister Theresa May outlined Monday a nine-point plan stating the rights of more than 3 million European Union (EU) citizens to remain in Britain after Brexit.

Telling MPs in a House of Commons debate that her post-Brexit proposals were a fair and serious offer, May said under the plan no EU citizen in Britain lawfully will have to leave when the country finally ends its membership of the EU in about two years.

She said any EU citizen in Britain with five years' continual residence at a specified cut off point will be able to stay with settled status and be treated as if they are British citizens in regard to healthcare, education, benefits and pensions.

Those without five years' residence arriving before the cut-off date will be able to stay until they have five years' residence and can then apply for settled status.

May added that the cut-off date will be the subject of discussions, but will be no earlier than March 29 2017 and no later than March 29 2019, the date Britain is scheduled to leave the EU.

The plan will also mean no families will be split up, with measures to allow dependents to apply for settled status.

May also said there will be no "cliff edge" by introducing a two-year grace period to allow people to regularize their status.

The policy unveiled by May will mean all 3 million EU citizens resident in Britain will have to apply for a settled status identity card.

It is also expected that the offer will be extended on a reciprocal basis to citizens of Norway, Iceland, Liechtenstein and Switzerland.

May's plans came under attack from opposition politicians.

The main opposition leader, Labor's Jeremy Corbyn, said the offer was not generous and offered too little, too late.

Labor said Britain should have made a unilateral guarantee to EU citizens following the referendum a year ago which voted in favor of Brexit.

Tom Brake, the Liberal Democrat's Brexit secretary, said: "Far from being 'fair and serious', this proposal offers very little and shows the government is continuing in its callousness."

He called for Britain to unilaterality guarantee the right of EU citizens to stay.