Ljubljana - Prime Minister Janez Janša is jeopardising the 2009 border arbitration agreement between Slovenia and Croatia and is abusing office as he engages in talks with Croatia on what was already agreed on, Matjaž Nemec, an MP for the opposition SocDems, said in Ljubljana on Thursday.

Nemec spoke to the press a day after a Croatia newspaper reported that Croatia and Slovenia had drawn up a pilot plan to solve the issue of fishing in the Bay of Piran.

The deal reportedly envisages a joint fishing area and annulment of all fines that have so far been imposed on fishermen from both countries.

The newspaper, breaking the news two days after Janša visited Zagreb, said the temporary solution would not prejudge the final agreement on the border at sea.

Nemec said that the new new fishing regime would enable Croatian fishermen to fish in Slovenian territorial waters, which are more rich in fish, "without disturbance".

This could lead to a point negating the agreement made under the auspices of the arbitration tribunal - a treaty endorsed in a referendum and in parliament, he added.

The arbitration agreement clearly says that if the two countries reach a bilateral agreement on border issues, the arbitration agreement can cease to exist, said Nemec.

What Slovenia negotiates on its territorial waters with Croatia "will remain so for good and will be irreparable", he stressed.

Nemec believes that such a fishing agreement could irreversible take bilateral relations back to the point when border issues would be addressed on a partial basis.

As a result of such an agreement, Slovenian fishermen would lose out due to the invasion of Croatian fishermen into the Bay of Piran, he said.

Croatia has achieved its foreign policy goals of the decade - joining the Schengen area and the eurozone and receiving an invitation to the OECD, whereas Slovenia has received in exchange Croatian fishermen being allowed to fish in the Slovenian sea, he said.

SD MP Meira Hot, who comes from the Slovenian coast, regretted that Slovenian fishermen had not been acquainted with the new agreement.

When the parliamentary Foreign Policy Committee met to debate secret agreements which had been revealed by the media, Foreign Minister Anže Logar was urged to include fishermen in all such agreements, which did not happen, she added.