The flow of Polish migrants coming to the UK will steadily decrease in the next few years as workers return to their home country and as Germany ends immigration restrictions.
Krzysztof Trepczynski, minister counsellor at the Polish Embassy, said large numbers of Poles would move back after gaining new skills in the UK.
The decision by Germany, which borders Poland, to ease restrictions on migrants will also make a huge difference, he said. Under EU rules, countries with restrictions must open their borders for good by April 2011.
Home Office figures published last week reveal that more than 300,000 Poles have signed up to the Worker Registration Scheme since May 2004. The figure does not include the self-employed or those not working.
Speaking at a roundtable event in London last week, Trepczynski said about one million people had left Poland since it joined the EU, and the government was now asking them to return.
"The economy is in more positive shape because Poles are sending money home and wages are rising," he said. "The long-term effect is more people will move back."