By STEVE DOUGHTY, Daily Mail

Last updated at 12:34 25 April 2006

Two million Poles have arrived in Britain since EU borders were thrown open to eight east European countries in 2004.

The influx - greater than the population of Warsaw - raises serious doubts over Government assurances about the impact of European Union expansion.

The figure, from the Office for National Statistics, records the number who have travelled to the UK, not the number who have stayed.

But it suggests that the growing army of workers establishing itself in Britain from Poland and eastern Europe may number many hundreds of thousands.

And a thinktank predicted today that around 56,000 Romanian and Bulgarian workers will come to Britain if their countries join the European Union next year.

The Institute for Public Policy Research (IPPR) urged the Government to give the new arrivals the same full working rights granted to eight other Eastern European nationalities in 2004.

Poles, whose travel until 1989 was severely restricted by the Iron Curtain, are visiting at a rate three times higher than they were before they were given freedom of entry.

They are now among the top 10 visitors to Britain, outnumbering Australians and Canadians last year and falling only just short of the total of visitors from Belgium or Italy.

At the same time they have become prominent over the last few years among workers in construction, catering and agriculture.

But the actual numbers working in the economy are notoriously difficult to count. The Government's Worker Registration Scheme attempts to record employees from the eight new EU countries. It currently lists 345,000 eastern European workers, including 205,000 from Poland.

But the scheme notoriously fails to include the self-employed and is thought to miss many workers who prefer not to be registered. Last autumn it said there were just 95 Polish plumbers working in Britain.

However, the Daily Mail gathered that number together in West London within 24 hours with one card in a newsagents' window and three phone calls.

Amid the confusion, only one estimate can be confirmed as entirely wrong.

Before the east Europeans joined the EU, the Home Office said that immigration of new workers from the region would run at the rate of 13,000 a year.

That has been shown to be at least 10 times lower than the true figure.

Ministers announced yesterday that the Worker Registration Scheme would continue. Immigration Minister Tony McNulty said that eastern European workers "have helped fill vacancies in parts of the economy experiencing labour shortages and have helped deliver public services".

"There is no evidence that the entry of workers from the new EU member states has impacted on the unemployment rate for resident workers," he said.

But independent economists said unemployment has shot up over the past year and that although eastern Europeans are boosting the economy and are welcomed by many, they are nevertheless presenting wage and job competition for a large number of British workers.

The two million figure for Polish visitors is projected from ONS estimates for travel and tourism in Britain between 2003 and 2005.

Its figures show there were 1.66million Polish visitors between April 1 2004 and the end of last year.

With Polish travellers now arriving at the rate of nearly 100,000 a month, the two million level is likely to have been surpassed by the second anniversary of the country's entry to the EU on May 1.

The population of the Polish capital, Warsaw, is just over 1.9million.

According to the ONS breakdown, there were over a million Polish arrivals in Britain last year, compared to just 325,000 in 2003.

Economist Ruth Lea, of the centre-right Centre for Policy Studies, said: "This month's unemployment figures show an increase of 30,000 over three months and 120,000 over the past year. Those are people who are really looking for jobs.

"It is very clear that migrant labour has kept down wages and it is highly questionable that immigration has had no effect on unemployment.

"Polish workers are welcome in many ways and by many people. But they are also competing for the same jobs with British people."

Meanwhile, the IPPR, often described as Tony Blair's favourite thinktank, estimated 41,000 Romanians and 15,000 Bulgarians would come to work in Britain in the first year. The two countries could join the EU from January 1, but a final date has not been set.

Official figures have shown the UK Government greatly underestimated how many Eastern Europeans would come to the country under the previous expansion.

Research suggested the annual figure would be no more than 5,000 to 13,000. But more than 345,000 signed up to a work registration scheme from May 1, 2004 to the end of 2005.

The IPPR said its 56,000 figure was based on what happened after the 2004 EU expansion.