Turkish voters have given strong backing to a package of constitutional changes.
According to provisional results, the changes, aimed at curbing the power of the army and reshaping the judiciary, have received almost 60% approval.
The package includes 26 amendments to the 1982 constitution, many of them backed by the European Union, the BBC reports.
The government says it wants to bring the constitution more in line with EU standards, but the opposition argues that the governing party, which has its roots in political Islam, is seeking dangerous levels of control over the judiciary.
"We have passed a historic threshold on the way to advanced democracy and the supremacy of law," Prime Minister Recep Tayyip Erdogan said to the applause of party activists.
Analysts say the strong "Yes" vote will boost Mr Erdogan's government.
His Justice and Development Party (AKP) will be seeking a third consecutive term in office in a general election due to take place before July 2011.
The AKP has clashed repeatedly with Turkey's highest courts, which see themselves as guardians of the country's secular values.