Turkey has lost control of its borders by opening them to Syrian refugees and been isolated on the world stage by meddling in the affairs of its neighbours, its main opposition leader said in an interview.
Kemal Kilicdaroglu, head of the secularist Republican People's Party (CHP), said Turkey's support for what he described as radical opposition groups in Syria had broken a tradition of neutrality and left Turkey exposed.
"Turkey's foreign policy has left it more isolated than ever, both from the European Union and the Middle East," Kilicdaroglu told Reuters in an interview a week ahead of a June 7 parliamentary election.
"The current government is interfering in the internal affairs of other countries directly ... This is against our past, our culture," he said, after addressing tens of thousands of flag-waving supporters in the capital Ankara on Sunday.
Turkey's oldest political party, the CHP was founded by Mustafa Kemal Ataturk, father of the modern republic, and has long been seen as the preserve of so-called "White Turks", the urban elite which ran Turkey for much of the 20th century.
The party, Turkey's second biggest, is campaigning on a platform of economic reform and of repairing international ties. But it is struggling to poll above 30 percent due to a lack of popularity among the pious masses suspicious of its secular ideals.
President Tayyip Erdogan's vision of a Middle East with political Islam and Turkey at its heart is anathema to CHP's secular and social democratic supporters.
"The burden of Turkey's foreign policy is falling on our people. More than 2 million Syrians are in Turkey, many of them begging on the streets," Kilicdaroglu said, warning some may "become involved in underground business".
"The government could have formed a buffer zone and kept refugees there safely. But they have pursued such a policy that left our Syrian frontier like a free passage zone, and we've lost the control of our borders," he said.
Under Erdogan's Islamist-rooted AK Party, Turkey has become one of Syrian President Bashar al-Assad's fiercest critics, pushing for his ouster, allowing the political opposition to organise on its soil and opening its border to refugees.
Syria and some of Turkey's Western allies say Turkey, in its haste to see Assad toppled, allowed fighters and arms across who went on to join the ranks of the Islamic State militant group.
Ankara has repeatedly denied arming Syria's rebels or assisting hardline Islamists.
Opinion polls suggest the AK Party will remain by far the biggest presence in parliament, but that it could fall short of the simple majority needed to avoid a coalition.
Kilicdaroglu ruled out any chance of a coalition with the AKP unless it showed a commitment to stamping out graft, and referred to a corruption scandal that swirled around Erdogan's inner circle in December 2013.
"If the AKP takes the Dec 17-25 corruption cases to court again and promises to put all the culprits before judges, that's another story," he said.
Thousands of police and hundreds of judges and prosecutors were reassigned in the wake of the scandal and the cases have since been dropped.
Erdogan has blamed the scandal on his former ally-turned-foe Fethullah Gulen, a U.S.-based cleric whose followers held influence in the police and judiciary.
Kilicdaroglu said Turkish society had become much more polarised since the AKP came to power in 2002 and that its record on rule of law, freedom of speech and gender equality had all deteriorated.
"Turkey has lost so much of its democracy in the last 13 years," the former civil servant said.