The U.K. government is planning to review its immigration policies, in a move likely to make it more difficult for foreigners to become British citizens. Home Secretary Alan Johnson plans to announce as early as Monday new proposals under which foreigners would have to score a certain number of points to become British citizens — a requirement already in place for people entering the country to work or study.

This would extend a system, modeled after one in use in Australia and introduced last year, that grades workers and students hoping to enter the U.K. on criteria including education, age and need for their skills. The changes were aimed at making it easier to slow the flow of foreigners looking for work in the U.K. when the economy weakens.

Further details of the new proposals weren’t immediately available, but a Home Office spokeswoman said their aim would be to “provide flexibility for the government to respond to the changing economic needs of the country.”

The move comes as unemployment is now at a 12-year high and as concerns about terrorism have fueled a surge in protectionist sentiment in the U.K., long one of the world’s most open countries. Earlier this year, workers at a number of refineries staged large-scale strikes to protest the use of foreign workers. Meanwhile, once-marginal anti-immigration politicians have been gaining ground.

The U.K. began tightening its immigration policies several years ago. The points-based system has raised hurdles for all but the most highly skilled workers to enter and live in the country.

The Home Office said its proposals will be put out for public and political consultation. The spokeswoman said the proposals would aim to strengthen the country’s current citizenship process, which already requires candidates to display good conduct, speak English and demonstrate that they are making a contribution to the community. “The points-based system has already proved to be a powerful tool for controlling migration for the benefit of both British people and the economy,” she said.

This week’s proposals will likely include changing a rule that allows workers who have been in the country for five years to apply for a passport, by making that period longer, a person familiar with the matter said.

This year, England, which receives the majority of the U.K.’s immigrants, is expected to overtake the Netherlands to become the most densely populated country in Europe. According to government calculations, immigration will add seven million people by 2031 to the U.K.’s population, which is currently more than 60 million. Critics say recent increases are placing a huge burden on public services, as hospitals and schools face increased demand but no increase in their budgets.

In elections last June, two members of the British National Party won seats in the European Parliament, the first electoral success for the anti-immigration party.

Other European countries also are clamping down on new immigration as their economies slow and citizens complain that too many people are being allowed in. Britain, however, with France and Germany, was among the first to open its borders to large-scale immigration from non-European countries after World War II.

Some industries have complained about the increased restrictions. Both Britain’s catering industry and its powerful banking sector have said that tightened immigration rules have made it harder for them to attract global talent and fill jobs that can’t be filled through local hires.

The points-based system was also criticized this weekend in a report by a committee of U.K. lawmakers, who said it gives undue priority to factors such as qualifications and ignores ability or experience.

Some critics, such as member of Parliament and former Labour government minister Frank Field, have said the points-based system’s effect has been trivial, and that it has reduced the number of foreigners looking for jobs in the U.K. by only 8%.