The European Union is launching an effort to contain the so-called "grey economy" of undeclared and untaxed work.

EU Social Affairs Commissioner Marianne Thyssen said Friday: "For us it is clear: there is no place for unfair working conditions and social dumping in our European Union."

In the grey economy, workers are often required to work long hours at low pay in unhealthy conditions. The evasion of taxes on labor, meanwhile, undermines Europe's efforts to sustain a welfare system.

Under its new plan, the EU will seek to exchange best practices to combat undeclared work among the 28 member states and boost common projects.