Piran Gulf. Photo: Wikimedia Commons

The dispute between Croatia and Slovenia over the Piran Gulf risks going up another notch after Croatian police offered to accompany Croatian fishermen in the waters of the Piran Gulf and ward off any Slovenian attempts to issue them with penalty notices.

The two former Yugoslav republics are locked in an unresolved dispute over the waters off the Istrian peninsula, which both claim.

Demanding that the Croatian state intervene, Croatian fishermen met the country’s Agriculture Minister, Tomislav Tolusic, and representatives of the Interior, Foreign and Justice ministries in in Zagreb on Thursday.

The meeting was called after Slovenian police on December 29 started implementing the ruling of the Permanent Court of Arbitration in The Hague, issued six months earlier. This awarded around 80 per cent of disputed water to Slovenia, granting Slovenia also a 2.5-nautical-mile-wide maritime corridor towards international waters.

However, Croatia quit the arbitration process in July 2015 after revelations that taped unauthorised conversations took place between a judge on the panel and a Slovenian diplomat. It therefore has decided to ignore the ruling.

With Slovenian police stopping Croatian fishing boats from entering waters that until recently were under Croatian control, fears have grown that they will receive tickets for illegal fishing, which could be collected whenever they cross the border into Slovenia. Fishermen demanded protection from the Croatian police.

After the talks with government officials, fishermen said that they were satisfied with the outcome, and would continue to consider the middle of the Gulf as the maritime border between the two states. The government has given guarantees that their interests will be protected.

“From tonight we sleep peacefully. Fishermen can work normally, the state is firmly behind us,” Daniele Kolec, representative of a fishing association, Mare Croatica, said after the meeting.

Croatian Foreign Minister Marija Pejcinovic-Buric on Wednesday said the only valid border for Croatia is the one from when both states declared independence from Yugoslavia in 1991.

“Both the one and the other side on June 25, 1991 further confirmed that this was an international border between the two countries,” she said.

She said Slovenia’s border police could not issue tickets to Croatian fishing boats, “since there cannot be a unilateral implementation of the arbitration [ruling]”, once more calling for a bilateral resolution to the dispute.

However, Slovenia’s Foreign Minister, Karl Erjavec, repeated on Thursday that Slovenia will not reopen discussions on the border in the Piran Gulf.

“Slovenia supports dialogue with Croatia on implementation of the verdict, but we will not talk about re-drawing the border,” he said.

“If the 1991 border was confirmed, then why did we talk about it at all?” he added, in reply to his Croatian counterpart’s statement from the day before.

The European Commission on Wednesday urged both states to continue dialogue and avoid any moves that could aggravate matters. It also again offered its help in implementing the decision.

The unresolved dispute is meanwhile in danger of becoming a hot issue for nationalist lobby groups in Croatian society.

The head of Croatian independence war veterans, Petar Janjic, on Wednesday warned Prime Minister Andrej Plenkovic that he had only “72 hours to resolve the problem with Slovenia”.

Otherwise, war veterans have threatened to organise a flotilla of 100 ships that would “protect the Croatian maritime state border with Slovenia”.