Slovenia warned Today that it could not accept without amendments a European Union mediation proposal in an ongoing dispute with neighbouring Croatia over its accession to the bloc, according to dpa. The pair have been at loggerheads for months in an obscure row over their joint border at the Bay of Piran, which is threatening to hold up Croatia's bid to join Brussels. "I hope that (EU Enlargement) Commissioner (Olli) Rehn will take into account our amendments. Otherwise we will not accept his proposal," Slovenian Prime Minister Borut Pahor told journalists, without giving any details. The Foreign Affairs committee of the Slovenian parliament should approve the government's decision on Friday, after which Slovenia will present its amendments to Brussels. For six months now Slovenia - an EU member - has been blocking Croatia's accession talks with EU over a long-standing dispute dating from the break up of former Yugoslavia in 1991. The border row has left Slovenia landlocked with its access to high seas cut off by Italy and Croatia. Rehn proposed to resolve the dispute by a five-nation arbitration court. The Croatian parliament last week agreed to Rehn's proposal, but Slovenia remained cautious. Earlier this week Slovenian government and members of the opposition agreed that changes in Rehn's proposal are necessary and that final decision should not be based only on international law but should take into account "historical rights" and equality principles. Croatia has more than 1,000 kilometres of coasts while Slovenia less than 50 but Zagreb refuses to move the border on the southern part of Bay of Piran and so allow free access of Slovenian ships to the sea.