Hungary's ruling Socialist party will ask the European Socialist Party's president to launch an investigation of Slovakia's latest steps in connection with its controversial state language law, the party's PM candidate Attila Mesterhazy told MTI on Thursday.

Mesterhazy said that the monitoring committee of the European Socialist Party had been set up to examine radical political manifestations targeting minorities, of which Slovakia's latest move to adopt guidelines for implementing its state language law is an example.

"By adopting guidelines to the amended state language law on Wednesday, Slovak Prime Minister Robert Fico has breached an earlier agreement with Hungarian Prime Minister Gordon Bajnai made in Szecseny," Mesterhazy said, in reference to an agreement on steps to ease the tension between the two countries over the language law, perceived by Hungary as discriminating against minorities in Slovakia.

The monitoring committee should see that the Slovak government's guidelines on implementing the law are against European norms, Mesterhazy added.

Katalin Szili, chairwoman of the permanent committee of the Forum of Hungarian Representatives of the Carpathian Basin (KMKF) -- an organisation which has been heavily attacked by Slovakia -- said after a closed-door meeting on Thursday, that the approval of the guidelines on December 16 could "further exacerbate relations between Hungary and Slovakia".