"It's evident that even President Josipovic realises, as do many political commentators, that Milanovic is not the real opposition leader, and by socialising with local SDP officials in Dubrovnik, he is actually suggesting that he is the real opposition leader and that he can bring the opposition to power in Croatia," Matusic told the press.

Asked if the HDZ's strategy was a political attack on Josipovic, he said there was no attack and that the HDZ was only commenting on the fact that Josipovic had recently socialised with local and top SDP officials in Dubrovnik.

Matusic denied Josipovic's claim that he attended a dinner organised by the city after the opening of the Dubrovnik Summer Festival, saying he had not been invited.

He said the HDZ's criticism of Josipovic had been prompted by his socialising with SDP officials also the day before the festival opened on Sunday night.

"Everything is more than clear. The president is, unfortunately, very actively involved in the (SDP's) election campaign, which is not envisaged by the constitution, and it's not good for the president to take any political side or advocate or promote any political option's interests," said Matusic.

Asked if HDZ president and Prime Minister Jadranka Kosor had banned him from meeting with Josipovic and if this was why he did not attend the dinner, he answered in the negative.

Asked by the press if the HDZ considered Milanovic or Josipovic the opposition leader, HDZ MP Krunoslav Markovinovic said Milanovic was "definitely" not the opposition leader. He added that Kosor had not banned him from socialising with Josipovic either.