BELGRADE, June 5 (Xinhua) -- On the eve of Sunday's referendum to determine whether to accept binding arbitration to resolve a border dispute with neighboring Croatia, opposition and ruling political parties in Slovenia had one final opportunity to share their messages with voters.

On Saturday, the opposition coalition held a rally in the center of Ljubljana, calling on Slovenes to reject the proposed binding arbitration agreement, saying it "compromised the sovereignty and territorial integrity of Slovenia," according to a report of the Slovenian news agency STA.

During the pre-referendum campaign, the ruling coalition emphasized that the agreement was in Slovenia's interest and would guarantee access to international waters, while the opposition bloc claimed the opposite.

President of the Slovenian National Party Zmago Jelincic said that adoption of an arbitration agreement would bring about "the end of the Slovenian sea port of Koper." He said that arbitration decision would deny Slovenia access to the sea, and stated that this was "not a fair solution."

At the heart of the issue is whether this former Yugoslav republic tucked between Italy, Austria and Croatia will have access to international waters. The border dispute between Slovenia and Croatia had also effectively put Croatia's European Union accession process on hold, until the prime ministers of the two countries, Borut Pahor of Slovenia and Jadranka Kosor of Croatia, in November 2009 agreed to abide by binding arbitration.

Although the Croatian parliament ratified the agreement, Pahor decided the issue should be put before the Slovenian public with a referendum.

According to the STA report, polls in the country generally indicate a spread of about five points in favor of the anti- agreement bloc, 45.8 to 40.4 percent.