KIEV, April 4 – A new row emerged between President Viktor Yushchenko and Prime Minister Yulia Tymoshenko, now over the role played by Viktor Medvedchuk, one of Ukraine’s most controversial politicians, in her government.

Medvedchuk, a powerful chief of staff of former President Leonid Kuchma, is thought to be the mastermind of massive manipulation and election fraud that had eventually triggered the Orange Revolution in 2004.