BRUSSELS (AFP) -- Some 20,000 Belgians demonstrated in Brussels Saturday against the erosion of their spending power as the country's months-old political crisis begins to hit people's pockets.

The demonstration called by the three main trade unions also protested at demands by parties representing the Flemish majority to split the national social security system along regional lines.
Demonstrators paraded amid a sea of green, red and blue flags -- the trade unions' colors --- and balloons. Police estimated the participation at 18,000, while organizers said 25,000 had turned up.
""This demonstration is being held to sound the alarm,"" said union leader Claude Rolin.
""Today, it's the three trade unions that are saying clearly to the political and economic forces that purchasing power must be reinforced and a federal social security system based on solidarity must be maintained. It is an appeal to reason.""
Unlike the country's political parties, divided linguistically, the trade union confederations are among the few organizations still functioning on a federal basis.
Together they represent some three million of Belgium's population of 10.5 million, who are split between the wealthier Dutch-speaking northern region of Flanders and the French-speaking southern region of Wallonia.
Flemish parties want more autonomy for their region, including in economic matters, and attempts to form a new coalition government since elections six months ago have all failed.
""Today we are launching an appeal to all politicians,"" said another union leader, Anne Demelenne. ""It is urgent to get to work on real problems: purchasing power, employment"", as well as ""reestablishing confidence among all citizens, in the north, south and in Brussels.""
The European Commission warned on Tuesday that the long-running political crisis is beginning to hit the country's economy, adding to concerns voiced by an employers' association and the national central bank.
The Commission blamed the situation on the fact that since the elections the country has been run by a caretaker government under outgoing Prime Minister Guy Verhofstadt which has been unable to take policy decisions.
Public anger has been growing recently over the political paralysis that has prevented work on more new policy initiatives.
Likewise, the country's business community is increasingly alarmed about the toll the political paralysis is having on the economy and the impact it will have in the eyes of foreign investors.
Union leaders on Saturday demanded a new government be put in place to allow action to be taken on social issues.
In the afternoon, they met with Verhofstadt, who ""listened attentively to their demands,"" according to a spokeswoman for one of the unions.
""We hope it can now be carried forward on the political level,"" she said.
On Monday, King Albert II tasked Verhofstadt with rapidly forming a new interim government ""to take care of urgent business.""