By Oana Lungescu
BBC News, Bucharest
Romania and Bulgaria have deplored plans to limit their workers' access to the labour markets of Britain and Ireland when they join the EU.
Bulgaria has said it will impose reciprocal bans
Romania's prime minister described the British decision as "unfortunate".
He said the UK government had caved in to populist demands from the conservative opposition.
Bulgaria said it was considering reciprocal measures for citizens from Britain, Ireland and other EU countries that closed their labour markets.
Labour restrictions are decided by each EU government and can be imposed on new member states for up to seven years.
Romania and Bulgaria feel they are taking the brunt of the popular backlash against EU expansion and migrant workers in Western Europe.
The Romanian Prime Minister, Calin Popescu Tariceanu, went live on television to say that Britain's Labour government had given in to populist pressures.
There was no threat of a massive surge of migrants, he insisted, because Romania had one of the highest rates of growth in Europe and very low unemployment.
Bulgaria went one step further, saying it would consider limiting the access of British and Irish workers in return.
That would be largely symbolic, reflecting the frustration in both countries that they are treated as third-class EU members - even worse than Poland and the other former communist nations that joined the club in 2004.
While Britain and Ireland are reversing the open-door policy they adopted two years ago, Sweden has hinted it may stick to it.
Finland has formally announced it would open its labour market for Bulgarians and Romanians, followed by several eastern European newcomers, notably Poland.
But Germany, France and other large member states seem unwilling to follow suit.
All eyes now are on Spain and Italy, where Romanians and Bulgarians are already working in their hundreds of thousands.
On 1st January 2007, they will become the poorest among EU citizens, but will gain the freedom to live and travel across the bloc and may simply be driven onto the black market.