"Posted workers'' from Eastern European nations including Romania and Poland continue to pay into the tax and social security systems of their home countries, allowing employers to hire them for less than in Western countries where welfare costs are higher. The majority work in construction, but many also work as welders, electricians or carers for the elderly.

Macron wants to require companies to pay posted and local workers the same salaries and limit postings abroad to up to one year.

Posted workers account for about 1 percent of the EU's total workforce, but they are perceived as pricing out local workers in Western Europe, putting downward pressure on wages and exacerbating inequalities in wealth.

Last year, the European Commission proposed new rules to regulate the issue, requiring companies to pay posted and local workers the same. But the proposals haven't won support from member states in central and eastern Europe.

Romania's National Pension House says last year some 50,000 Romanian workers were posted abroad to other EU countries.