Lithuania's population has slumped by more than one tenth in the past decade, after hundreds of thousands of people emigrated to richer west European nations, census data showed on Monday.

Preliminary figures revealed that 3.05 million people now live in the Baltic republic, compared with 3.48 million in 2001 when the last census was conducted.

In 1989, the year before Lithuania declared independence from the Soviet Union, its population had been 3.67 million.

The slump is a concern for the country's centre-right government, which is at the helm of a tough austerity drive brought in after Lithuania plunged into one of the deepest recessions in the European Union in 2009.

The economy has gradually emerged from the doldrums after the sharp crisis.

"It is very important that those people who left Lithuania in large numbers keep ties with Lithuania and see opportunities to come back," Prime Minister Andrius Kubilius told reporters on Monday. Analysts warn that the population decline may impede the economic recovery.

"The population decrease has been very rapid due to negative demographic trends, but emigration is probably even more important," Rimantas Rudzkis, chief analyst at the bank DnB Nord in Lithuania, told AFP.

"Such a decline will have negative consequences. Lithuania will be lacking workforce and that may deter investment," he added. The emigration trend started after EU entry in 2004.

Hundreds of thousands of Lithuanians have sought a better life abroad, notably in Britain and Ireland which opened their labour markets immediately to citizens of new, ex-communist EU member states.

Few have returned, despite the host countries' own economic slumps. Statistics showed that 83,500 people left Lithuania in 2010, mostly to Britain and Ireland.

Officials have said that may include people who left earlier but made the move official to avoid the Lithuanian government's new drive to collect taxes from undeclared emigrants.  -AFP