Turkey opposition leader vows to bring democracy back at huge rally

The leader of Turkey's main opposition party on Sunday addressed a huge rally in Istanbul at the culmination of an almost month-long march, promising to bring democracy to the country, in a rare challenge to President Recep Tayyip Erdogan.

Kemal Kilicdaroglu, the leader of the secular Republican People's Party (CHP), started an unprecedented 450km trek on 15 June from Ankara to Istanbul in protest against the arrest of one of his MPs.

"This march does not end here. This is just he beginning," he told the vast crowd, thought to be the biggest centre-left rally since 1977, when former prime minister Bulent Ecevit was elected.

"We will definitely bring first-class democracy to this country. Everyone will be able to express themselves," he declared.

"Everyone should know very well that July 9 is a new step, a new history... a new birth," he added.

Supporters have compared the trek of the slightly built, mustachioed 69-year-old with Indian independence leader Mahatma Gandhi's famous "salt march" of 1930. The government has dismissed the march as a bothersome stunt.

Hundreds of thousands of people were thought to be in attendance in Istanbul, with some estimating that number at around at least 1 million. 

The rally could be one of the biggest opposition protests seen in Istanbul since the mass 2013 demonstrations against Erdogan's rule sparked by the planned redevelopment of Gezi Park in the city.

The CHP leader reached the outskirts of Istanbul on Friday and was joined by tens of thousands forming a vast file along the road despite blistering heat.

On Sunday, he walked the final three kilometres alone before joining the waiting crowds at a vast meeting space in the Istanbul district of Maltepe.

"Why do I walk? This 450-kilometre march has one goal: Justice," Kilicdaroglu said ahead of the meeting.

"They ask 'Can we seek justice on the road?' Yes we can. If there are grave injustices and illegalities in your country and if your country's courts are incapable of delivering justice, you will stand up and hit the road," he said in a statement to AFP.

Kilicdaroglu started the march from Ankara after his party's lawmaker Enis Berberoglu, a former journalist, was sentenced to 25 years in jail on charges of leaking classified information to a newspaper.

The rally ground is near Berberoglu's prison in the Istanbul district of Maltepe. 

Carrying simple insignia emblazoned with the word "Justice" without any party slogans, he turned the march into a protest for those who feel unfairly treated in Turkey under Erdogan.

Kilicdaroglu had said he wanted no party insignia, only "Justice" slogans and pictures of modern Turkey's founder, Mustafa Kemal Ataturk, at the Maltepe rally.

About 50,000 people have been arrested under Turkey's state of emergency imposed after last July's failed coup and another 100,000 have lost their jobs, including teachers, judges, soldiers and police officers. 

Kilicdaroglu has strongly condemned the failed coup bid - blamed by the government on US-based preacher Fethullah Gulen, who denies the charges - but has been bitterly critical of the scope of the state of emergency.

In the latest crackdown, Turkish police on Wednesday detained Amnesty International's Turkey director and other activists on charges of membership in a terror group sparking a new uproar among rights advocates.