Britain leaving the European Union could reduce net migration by 100,000, according to pressure group Migration Watch UK.
The group, which campaigns for cutting migration to the UK, today released a report that found Brexit would lead to net migration falling dramatically from its current level of 180,000.
"It is time to examine possible alternative immigration regimes. Under the current arrangements all the signs are that EU migration to Britain will continue at a substantial rate for the foreseeable future," Lord Andrew Green, chairman of Migration Watch, said. "Net EU migration now amounts to 180,000 a year. Work permits for EU citizens would substantially reduce net migration and its resultant pressure on our population and public services."
However, pro-In campaign Britain Stronger In Europe hit back, labelling the report "disingenuous".
"This disingenuous report is another example of the Leave campaigns fudging the facts because they know they're losing the argument," Britain Stronger in Europe spokesman James McGrory said.
"Freedom of movement isn't on the ballot paper - and neither Leave campaign even proposes ending it. As Norway, Switzerland and Iceland all show, access to the single market comes hand in hand with freedom of movement. To suggest we can simply pick and choose which bits of Europe we like after voting to leave is a dishonest fantasy," he added.
While the Migration Watch report looks at a variety of different policies that could be introduced after Brexit, the settlement that the UK would come to with the EU would depend on post-exit negotiations.
Still, the report said that a work permit system "could substantially reduce the EU inflow for work to perhaps one fifth of its recent level and would, in turn, substantially reduce net migration by perhaps 100,000 a year from the current level of 180,000".
It added that EU citizens living and working in the UK currently would retain their rights and EU citizens should still be able to visit the UK for business or tourism without the need for visas. EU students would also not be restricted.