Poland looks to Schengen deal in September

The Polish minister suggested that a compromise may be formed on gradual accession, with airports included first in the common border area, while sea and land borders would be opened at a later stage. Special Schengen terminals separating intra-EU flights from those from beyond Europe have been set up in both countries, which initially hoped to join the area in March.

As a former Communist country and a strong supporter of European re-unification, Poland insists that the promises made to Bulgaria and Romania need to be kept, especially since the technical requirements have all been met for the two to join Schengen.

With Bulgaria holding presidential elections in October, "unjustified" further delay may have political consequences, the minister warned.

But the Dutch interior minister on Thursday made clear that his government thinks it is still "too early" to take any decision on the matter before 2012.

Asked about the Dutch position, the Polish minister said it had "a different background" and that "up until recently, others were reluctant too but have meanwhile changed their mind." "We hope the Netherlands will change its mind as well," he said.

France, who last year wanted to delay Romania's Schengen entry due to a row over repatriations of ethnic Roma, in December joined the Dutch and the Germans in voicing concerns over corruption in the new EU state and warned against "premature" accession to the border-free area.

On Thursday, however, French interior minister Claude Geant suggested that phased-in entry may be an acceptable compromise, involving "a first stage in autumn with the opening of air borders in the presence of police from other states."

"A second stage could take place later, in 2012, with the opening of land borders, there again with the help of border guards from other EU countries."

All eyes are now on the EU commission, due to publish a report next month assessing how the two countries are fighting corruption and organised crime.