France's Prime Minister has criticised rich citizens fleeing the country's tax on high earners, saying they were greedy profiteers seeking to "become even richer".

Jean-Marc Ayrault's spoke out after France's best-known actor, Gerard Depardieu, took up legal residence in a small village just over the border in Belgium, with hundreds of other prosperous French nationals seeking lower taxes.

"Those who are seeking exile abroad are not those who are scared of becoming poor," Mr Ayrault declared after unveiling sweeping anti-poverty measures to help those affected by the economic crisis.