MOSCOW, October 2. /TASS/. Russian lawmakers will join a parliamentary assembly of the OSCE in Switzerland to challenge the legitimacy of Ukraine's president and its parliament.

They travel to Geneva on Thursday also to question changes to Ukraine's state constitution and to present analysis of human rights violations in the war-torn eastern Donbass region.

Deputies led by Duma Speaker Sergei Naryshkin will present a report as delegates to the Organization for Security and Cooperation in Europe's group gather for their autumn session, Vladimir Pligin said Thursday. Vladimir Pligin is the head of the Duma committee for constitutional legislation and leader of a Russian working party studying laws being adopted in Ukraine.

A report from the group published on September 30 said the Ukrainian constitution had been changed unlawfully and that the legitimacy of activity by the state parliament and its president was doubtful. Deputies also analysed laws recently adopted in Kiev to grant special status for the Donbass region and amnesty for militia forces.

These documents conflicted with Ukrainian law and therefore were impracticable, they said. “Adoption of such laws shows that implementation is not desired," the deputies noted, adding that "It seems gross violations when writing the laws were made intentionally”.

Law on power lustration - disqualification of anyone linked to a former regime's abuse of power - also contradicted international law and the practice of the European Court of Human Rights, they said.

An interparliamentary contact group on Ukraine, formed on Duma Speaker Naryshkin’s initiative during the last OSCE session, meets for the first time on the sidelines of the Geneva gathering.

Its main goal is to develop recommendations for a peaceful settlement of the Ukrainian crisis and provide the OSCE with objective information about the situation in embattled southeast Ukraine.