"Swedish collective agreements shall apply for everyone working in Sweden", top candidate Marita Ulvskog told Swedish news agency TT.
The Social Democratic group in the EU have said they won't re-elect European Commission chairman José Manuel Barroso unless he agrees to reform the directive.
On Sunday the Swedish Social Democrats presented their plans for reform. They want the directive to clearly guarantee the principle of equal pay and conditions for workers in each member state. They want it to enable countries to set tougher demands than those in the directive if they wish, and for it to state that all labour market models, including the Nordic one with its collective agreements, must be followed.
But top conservative Moderate candidate Gunnar Hökmark told TT that he thinks changes to the directive could be dangerous, claiming that it could mean that minimum wages are introduced all across the EU that are way below Swedish levels.