Bulgarian and Romanian migrants will have to show they can fill skill gaps before being allowed to work in the UK, according to reports.
Migrant workers are filling labour shortages, ministers say
The government is under pressure to impose working restrictions when Romania and Bulgaria join the European Union next year.
The Guardian newspaper quotes an anonymous Cabinet minister saying there will be a work permits system.
The Home Office did not deny the story but insisted no decision had been made.
'Politics over economics'
Recent immigration figures have increased fears that public services are being put under strain in some areas.
The government says about 600,000 people, including self-employed workers, have come looking for work in the UK since eight countries in eastern and central Europe joined the EU in 2004.
No restrictions were put on migrants from those countries, although they do have to register to work.
Ministers say the migrants have filled gaps on the labour market and helped keep inflation down.
But the Guardian says there will be a work permits scheme when Romania and Bulgaria join.
The newspaper quotes the unnamed Cabinet minister saying: "We have a strong record on accepting migrants from Europe, but sometimes politics has to override the economics and that is what is going to happen in this case."
The report suggests that relatively few potential migrants are expected to be able to show they have the skills needed to get the new work permits.
The permits would be similar to the points-based work permits scheme used for migrants from outside the EU, which stresses university education, professional qualifications and potential earning power.
The newspaper says the plans are supported by the Department of Work and Pensions, the Home Office and the Treasury, but have not yet been discussed by the Cabinet.
A Home Office spokeswoman said no decision had yet been taken on what access Romanians and Bulgarians would get to the UK labour market.
"A decision will be made after we know the date of accession for these two countries," she said.
"The decision will be based on objective factors in the interest of the British economy, including an evaluation of the UK's labour market, the impact of the previous enlargement in 2004 and the position of other EU member states.
"We are, of course, also seeking the views of key groups prior to any decision, including business leaders, trades unions, local authorities, and police services."
But shadow immigration minister Damian Green said it seemed the government was taking the Conservatives' advice.
"We called for this two weeks ago and, subject to looking at the detail, we would approve," said Mr Green.
"However, it is important that this amounts to more than just another exercise in grabbing a day's headlines and signifies a real shift in policy."