* Ahmed Dogan accused of possible political corruption
* Case key for Bulgaria's efforts to crack down on graft
SOFIA, Aug 4 (Reuters) - The leader of an opposition ethnic Turkish party in Bulgaria will stand trial for graft next month as the government tries to clean up its image as one of the EU's most corrupt countries, court officials said on Wednedsay.
Ahmed Dogan, whose Movement of Rights and Freedoms party was part of the previous Socialist-led coalition, will appear before the Supreme Administrative Court on Sept. 2 after a parliament commission on corruption notified it of a possible conflict of interest.
The commission said Dogan received 1.96 million levs ($1.33 million) in consulting fees on hydro energy projects in 2008 and 2009 while his party was in power, but failed to make public his link with the Bulgarian company that contracted him.
"The failure to declare... shows Dogan has concealed economic and political dependencies," the commission said.
Dogan has not commented personally on the accusations but a spokeswoman for his party said he denied any wrongdoing.
The case is not a criminal one and Dogan has not been arrested. If found guilty, he will be fined and asked to return the fees.
The centre-right government, which came to power last July, was lauded by the European Union last month for its will to crack down on organised crime and corruption but said Bulgaria still needs to improve its slow and often inefficient judiciary.
Analysts and commentators say the case against Dogan, the country's longest serving party leader, will be a test for the Balkan country's court system and its will to reform.
Dogan, a philosophy graduate, was hired by a Bulgarian subcontractor to give technical advice on the hydropower complex Tsankov Kamak in southern Bulgaria and on another project.
The commission said Dogan lacked the expertise to do the job. It said that under the previous ruling coalition, decisions on key issues for Bulgaria were taken by a council of party leaders and not the government.
"This way of taking decisions...makes existing political and economic dependence particularly dangerous and gives grounds to conclude that there is political corruption," the commission report published on the parliament's website showed.
Dogan is a founder of the Movement of Rights and Freedoms party, which politically represents the ethnic Turks and other Muslims who make up about 12 percent of the population.
A post-communist kingmaker, Dogan at times has undermined previous governments by blocking privatisations and holding budgets hostage in the interest of business allies, analysts and diplomats say.
(Reporting by Tsvetelia Tsolova; Editing by Elizabeth Fullerton)
Our Standards: The Thomson Reuters Trust Principles.