Provisional numbers from the Office for National Statistics suggest the number of people from east Europen countries fell by a third in the year to June 2009.
There were 68,000 new arrivals from the new European Union states, compared with 100,000 in the year to June 2008.
Figures show there was little change in long-term immigration or emigration.
The statistics also show that the number of asylum seekers has fallen significantly for the second quarter.
In the three months until the end of 2009, there were 4,765 asylum applications, down 30% on the same period of 2008.
The number of unauthorised migrants who voluntarily left or who were deported was 16,340 between October and December – down 3% on the previous year.
Other figures show that the number of people seeking British citizenship rose by almost a third in the last quarter of 2009, reaching 51,315. Almost 45,000 people who had applied were granted a British passport over the same three month.