The European Parliament's president has insisted fears of an influx of people from new EU states are exaggerated.
The Czech Republic is just one of 10 countries joining on 1 May
Pat Cox warned existing European countries to take a more generous approach to the 10 new members.
His comments came as Tony Blair was in Berlin for a tri-lateral summit with France and Germany.
British ministers are believed to have decided to limit access to UK benefits while giving the green light to new EU citizens who want to work here.
Home Secretary David Blunkett announce details of the new package on Monday about the new policy, but it is believed to place limits on access to the British benefits system.
There had been suggestions that Mr Blunkett and Mr Blair were at odds over what policy to take over the new EU states.
NEW EU MEMBERS (FROM 1 MAY)
But Trade Secretary Patricia Hewitt denied there had been rows in the Cabinet.
"We had very good discussions in the Cabinet and we are all very clear that the concession we made to the accession countries was absolutely right and we are not going back on that," she said.
Ms Hewitt told BBC Radio 4's Today programme that suggestions of huge numbers of people arriving from countries such as Latvia and Slovakia were "nonsense".
There were gaps in the UK labour market which the 10 new EU states could help fill and that would benefit Britain's economy, she said.
"What we don't want is our benefits system being exploited by people who frankly don't intend to work," she said.
The UK did not initially plan restrictions on new EU members
But ex-Europe minister Keith Vaz said any restrictions went back on clear commitments given by the government to "treat the citizens of new EU countries as equals".
"It is a commitment that I gave and other ministers gave over a period of time and it put us in a completely different league to other big countries in Europe," he told BBC Newsnight.
"It is a grave mistake and dances to the wrong agenda."
Britain and Ireland are the only two states allowing citizens from the accession nations of mainly Eastern European countries the right to work from 1 May.
In addition to restricting access to benefits, the new policy could include a work permit scheme.
Mr Cox told Today that when the Berlin Wall fell there had been fears of an influx of people from the former Eastern bloc but two thirds of those had returned home.
"That was also the experience with Spain and Portugal when we enlarged the Union in the 1980s," he said.
"France and others feared floods of migrants coming north - it didn't happen and the rules that they put in place fell into disuse.
"One hopes that that will be the experience in the months and years to come with these new states."
Mr Cox acknowledged there was the temptation of higher wages but there were other ties that kept people in their home state, such as family.
The Tories last week accused the government of being confused about their policy toward people from new EU states.
This came after Mr Blair first indicated Britain was looking at tighter controls and then Mr Blunkett insisted there would not be measures to discourage people from heading to the UK to work.
Existing EU members can impose transitional restrictions for up to seven years on the right of residents of eight of the ten new EU member states to work and claim benefits.
A separate deal means that there are no restrictions on citizens of Cyprus and Malta.