The European Union is very concerned about weak rule of law in Bulgaria, and Sofia must soon show results against graft and crime if it is to join next year as planned, the bloc's enlargement chief said on Thursday, according to Reuters. Despite robust economic growth and reforms in agriculture, intellectual property rights and other areas, the Balkan state has yet to fully prove its readiness for accession, said EU Enlargement Commissioner Olli Rehn. "There are still serious concerns about the rule of law," Rehn said during a visit to Sofia. "I am referring to the judiciary, where we need accountability and independence and to the fight against corruption and organised crime where we need concrete, tangible results ... to show that nobody is above the law." Rehn said Sofia had until the end of the month to prove it can tackle the problem, or the executive Commission can recommend in a May 16 report to delay its membership until 2008. The Commission may also ask EU states to allow Bulgaria to join next year, but to quarantine its judiciary or other sectors with so-called "safeguard clauses" under which they would be isolated from the wider Union. "The proposal will be a carefully calibrated decision, which aims at keeping up the momentum of the reform drive up to and beyond accession," said Rehn. "The accession date of 2007 is still doable." The EU has lauded neighbouring fellow candidate Romania, where prosecutors have stepped up the fight against high-level graft, charging a number of high-level officials, including former Prime Minister Adrian Nastase and other ex-ministers.