FEARS that an influx of Romanians and Bulgarians to Britain will put a strain on public services are downplayed in an independent report, published by the Foreign Office.

But the number that may arrive on UK shores after immigration restrictions are lifted next year remains unpredictable, according to the National Institute of Economic and Social Research (NIESR) study today.

Schools were likely to take much of the strain but the effect on the NHS, the housing sector and the welfare system will be less pronounced, it said.

Bulgaria and Romania joined the European Union in 2007 but under transitional arrangements workers from the two countries were prevented from travelling to the UK.

According to a British Labour Force sample survey, there are currently 26,000 Bulgarians and 80,000 Romanians living in the UK, but the actual numbers could be larger.

Last month, Communities Secretary Eric Pickles admitted the Coalition Government had "no idea" about the size of the possible influx.

However, initially at least, the impact on public services will be modest, with the strain only potentially increasing if Romanian and Bulgarian migrants choose to settle in the UK on a long-term basis.

Because most migrants will be young – mainly under-35 – and healthy, without families, they will have a minimal impact on the health service, it said.