Brussels - Four more European Union countries Thursday opened up their labour markets to workers from Bulgaria and Romania, but rich nations such as Britain, France, Germany and Italy continue to maintain restrictions.

Greece, Spain, Hungary and Portugal all agreed to welcome Bulgarian and Romanian workers, European Commission officials said, while Denmark said it planned to lift restrictions on all EU workers as of May 1.

But workers from Bulgaria and Romania are still expected to face obstacles in 10 other EU countries for some time to come.

Many EU governments had asked to be able to prevent Bulgarians and Romanians from freely entering their countries when the two joined the bloc in 2007, amid fears of a massive influx of immigrants from Eastern Europe.

But a November report by the EU executive concluded that such fears have not materialized.

The EU's employment commissioner, Vladimir Spidla, encouraged all member states to lift their restrictions as soon as possible, saying the economic downturn was not a valid excuse for keeping labour markets closed.

"Workers go to where there is demand for labour, not to be unemployed in another country," Spidla said.

EU governments can maintain some restrictions on the free movement of workers until the end of 2013, but only if they can demonstrate that lifting them would cause "serious disturbance" to their labour markets. (dpa)