BRUSSELS (Reuters) - The European Union reached a tentative agreement on Thursday to tighten employment rules for workers who move to richer member states in order to earn more money, a practice some countries say can be used to undercut wages and labour rules.

French President Emmanuel Macron poses during a visit to the Stade de France to attend the inauguration of the Olympic Committee site for the Paris 2024 Olympic games and 2024 Paralympic games in Seine-Denis, Paris, France, on February 27, 2018. REUTERS/Ludovic Marin/Pool

French President Emmanuel Macron has spearheaded the initiative to reform the system known as “posted workers” to quell discontent among his voters.

Currently workers from poorer EU countries can be employed in other member states on contracts that only need to guarantee the host country’s minimum wage, while social security charges - much higher in western states like France - are paid back home.

“At the heart of our proposal was the principle of equal pay for equal work in the same place, and we now confirm this in legislation,” EU Social Affairs Commissioner Marianne Thyssen told a news conference.

Thyssen, who has been holding talks with representatives of member states and the European Parliament, declined to give details of the tentative accord before reporting back to EU national governments. The deal must still win the approval of member state governments and EU institutions to become law.

A source at the French presidential palace called the deal “very positive”, saying it limited the length of stay abroad and adhered to the principle of “equal work, equal pay”.

Poorer EU member states in the ex-communist east have been reluctant to change a system that has given them a competitive advantage over richer neighbours and allowed their nationals on assignment abroad to earn more than they could back home.

“The negotiators managed to overcome the difference between East and West, left and right and employers and employees,” said Agnes Jongerius, a negotiator on behalf of the European Parliament, who also declined to provide details on the accord.

The debate among richer and poorer member states over cost competition is not limited to workers on assignment abroad.

Recently, the case of a white goods maker relocating from Italy to Slovakia stirred emotions ahead of Italy’s national election on Sunday.