More than 3.5 million eastern and central Europeans have visited Britain since the European Union opened its doors to eight new member states from behind the former Iron Curtain.
The figures provide graphic evidence of the political and cultural changes in Europe over the past two years, with almost four times more arrivals than before the EU's expansion.
The vast majority of the visitors were holidaymakers, demonstrating how western Europe - forbidden to most ordinary citizens under Communist rule - is now within the reach of affluent tourists from the new EU members. Ryanair, the budget airline, flies to eight Polish cities.
Growing numbers are also coming on short business trips as economic links strengthen between Britain and such flourishing economies as Hungary and the Czech Republic. The number of eastern and central European students at British universities is increasing.
Only about 10 per cent of the new arrivals (345,000) came to work for more than three months, filling skills shortages in agriculture, food processing, catering, construction and social care. Many headed to London and the South-east, but there are also relatively high numbers of workers from "accession countries" in East Anglia and the East Midlands. There are significant numbers in Northern Ireland, west Wales and Cornwall.
The changing patterns of population movement around the continent emerged in figures from the Office of National Statistics. They disclosed that 3.2 million visitors from Poland, Hungary, the Czech Republic, Slovakia, Slovenia, Lithuania, Latvia and Estonia came to Britain between May 2004, when the EU took in eight new members, and the end of 2005. Another 370,000 have visited the country in the first two months of this year.
By far the largest number - 1.7 million - were from Poland, which has strong historic links with Britain. Many of them will have been visiting relatives among the estimated 750,000-strong Polish community.
They were followed by 420,000 Czechs, 344,000 Hungarians, 283,000 Slovakians, 194,000 Lithuanians, 119,000 Latvians, 84,000 Slovenians and 66,000 Estonians.
The Institute for Public Policy Research (IPPR), the left-of-centre think-tank, said the trend could accelerate next year, when the EU is likely to expand to take in Romania and Bulgaria. It estimated 41,000 Romanians and 15,000 Bulgarians would come to work in Britain in their countries' first year of membership.
Danny Sriskandarajah, associate director of the IPPR, said: "It is far more than just people travelling for work - it is students, investors, British people buying property abroad and hundreds of thousands of holidaymakers."
The IPPR urged the Government to give new arrivals from Romania and Bulgaria the same full working rights granted to the eight other Eastern European nationalities in 2004.
A final decision on when the two countries join the EU will be taken in June. After that, the Government will have to decide how to respond, balancing evidence that eastern European workers have boosted the economy against the risk of a backlash from right-wingers hostile to the prospect of an influx of Romanians and Bulgarians.
A report from the forecasting group, the Ernst & Young Item Club, said migrants from the eight new EU members helped keep British interest rates down.
Tony McNulty, the Immigration minister, said: "The Government's decision to open its labour markets to nationals of the new member states immediately upon their accession to the EU has been vindicated. Nationals of the new member states have entered the United Kingdom to work, have helped fill vacancies in parts of the economy experiencing labour shortages and have helped to deliver public services. There is no evidence that the entry of workers from the new member states has impacted on the unemployment rate for resident workers."
Tomas Sojka, 23, from Slovakia : 'I was struck by London's multicultural nature'
Tomas Sojka was most struck by the multicultural nature of London when he arrived two years ago.
Having grown up in Dolny Kubin, a small mountain town in Slovakia, he found himself sharing a house with a Colombian and spending his days learning English with many other nationalities.
"I had been learning English for six or seven years but when I came here I couldn't understand anything. I had thought I was quite good and realised I was quite rubbish," explained the 23-year-old yesterday.
Penniless for his first few months, the expansion of the EU made a dramatic difference as he could get a job. He went to work in a south London gastro pub.
"I really enjoy living here," he said, "but I don't think I would like to stay for ever."
Alexandra Dziubani, 27, from Poland: 'Better jobs are available in the UK'
Alexandra Dziubani wasted no time when the opportunity of work in Britain came up two years ago. She was granted a work permit on 5 May 2004 - four days after her native Poland joined the EU - and became the proud possessor of permit number 000001 after being offered a job with Tribal Advertising in Manchester.
She arrived with a degree in history and politics and the advertising agency took her on as an account administrator.
There were emotional hardships, as she missed Poland, but her contribution to Tribal was helped by the English she learnt during four months in the US. "Better jobs are available and the money is much better," she said. "I want to work hard and build a life here."