The discussion took place on POP-TV on Thursday evening.
The leader of the Liberal Democrats, Prime Minister Anton Rop, said relations with Croatia were "quite tangled".
He said he and Croatian PM Ivo Sanader agreed in June that the incidents which usually occurred in Piran Bay in August would be avoided this year, and that he cautioned Sanader about the incidents recently, when they reoccurred.
"The incidents are caused by the Croatian and not by the Slovene side. We expect Croatia
to behave in a European manner," said Rop.
Slovene National Party leader Zmago Jelincic said former Slovene PM Janez Drnovsek and Foreign Minister Dimitrij Rupel committed "national treason" when they consented to "the division of Piran Bay".
Associated List of Social Democrats leader Borut Pahor said Slovenia was in an excellent negotiating position regarding the northern Adriatic bay because it was a member of the European Union and NATO.
New Slovenia leader and former PM Andrej Bajuk said the Rop Cabinet "didn't have clear positions" about the border with Croatia, thus undermining Slovenia's negotiating position. He added Slovenia must never give up the possibility to block Croatia's EU entry as long as the border issue remained unsolved.
Slovene Popular Party (SLS) leader Janez Podobnik said all Slovene parties should endorse the position of SLS candidate Jozko Joras that Istrian hamlets south of the Dragonja river are on Slovene territory. He opposed the idea of agreeing to Croatia's "fait accompli policy" on the border.
Democratic Party leader Janez Jansa disagreed with Jelincic's assessment that the border agreement initialled by the two countries' prime ministers was "disastrous", saying that what was disastrous was the conduct of the Slovene government after the agreement was initialled, which he added started acting as though the agreement was valid. Jansa slammed Rop's statement that the agreement would serve as the basis for arbitration, saying that if that were so Slovenia would get less than was envisaged by the agreement.