"This is flippant. They (officials of the Janez Jansa cabinet) can do nothing but point to something that was allegedly done poorly," Drnovsek was quoted by the RTV Slovenia broadcasting company as saying on Sunday.
"Before we at least made some attempts to solve the border problems, and we made considerable headway. Now there are no attempts at all," Drnovsek said.
The current Slovene premier, Janez Jansa, told a party conference of his Slovene Democratic Party (SDS) in Izola that he had inherited a poor situation from the previous governments regarding Slovenia's relations with neighbouring countries.
The border demarcation in the contested area along the Mura River and relations with Croatia usually become topical in exchanges of barbs between major Slovene political parties ahead of elections. The new local elections in this Alpine country are scheduled for 22 October.