The leaders of France and Germany have called jointly for countries using the euro to have common corporation and financial transaction taxes.
The proposal is in a letter to European Council president Herman van Rompuy on the eve of a summit in Brussels to discuss the eurozone debt crisis.
President Nicolas Sarkozy and Chancellor Angela Merkel also want changes to EU treaties to enforce budget discipline.
Their letter called for "a renewed contract between the euro area member states".
Meanwhile, a senior German official has told the BBC that some countries still do not understand just how serious the situation is.
