Thousands marched through the streets of the Mediterranean city of Adana in protest at the arrest of its mayor on alleged corruption charges. The mayors of Antalya and Adiyaman have also been detained on similar charges. More than a dozen mayors of Turkey's main opposition CHP have now been jailed.

The legal crackdown began in March with the jailing of Istanbul's mayor, Ekrem Imamoglu, and on Wednesday, President Recep Tayyip Erdogan vowed there would be no letting up.

"We launched an investigation into the largest theft ring in the history of the Republic, the most reckless organised crime organisation ever," Erdogan told his parliamentary deputies.

"Those who took bribes, those who practically held cities under extortion, those who put people in a difficult situation and then robbed them were all CHP people," he continued.

Erdogan further ratcheted up the pressure on the CHP with a presidential motion calling for the lifting of parliamentary immunity from 61 out of CHP's 121 deputies.

CHP leader Ozgur Ozel is also under investigation for allegedly inciting public hatred and insulting the president.

Ozel is at the forefront of leading anti-government protests across the country, which continue to attract large crowds as the party builds a significant lead in opinion polls over Erdogan's Justice and Development Party (AKP).

The CHP claims their growing success is what is motivating the recent prosecutions, rather than corruption. "These are politically driven arrests and investigations," declared party spokesman Ilhan Uzgel. "Not a single government party mayor is even investigated."

Uzgel admits that with more than 500 of its officials having been arrested, the party is facing a battle for survival. "The government has all the instruments of the state. They control the judiciary, they control the police force etc etc. So it's very difficult to stop it."

Despite mounting pressure, however, Uzgel insists they will not back down.

"We are organising rallies twice a week, our leader is very energetic. He [Ozel]... said we are not going to back down. The government, they don't want the opposition party to challenge Erdogan's authority. This is the core of the issue right now."

Turkey walks a fine line as conflict between Israel and Iran cools

However, the political noose around the neck of the CHP continues to tighten. This week, the opposition Sozcu TV station was banned for 10 days by regulatory authorities for "inciting public hatred" after broadcasting protests against the jailing of the Istanbul mayor, Ekrem Imamoglu.

Another opposition TV station, Halk, is facing a similar ban. The two are among the few media outlets that continue to report on the ongoing CHP protests against the waves of arrests.

The broadcast bans are being seen as a sign that the days of critical media could be numbered.

"I believe by the end of this year we might be hearing of the start of the liquidation of critical TV channels," claims Erol Onderoglu, Istanbul representative of the Paris-based NGO Reporters Without Borders.

Fears are growing too that the threat against independent media is part of a much more worrying process of the dismantling of the pillars of democracy.

Turkey steps into EU defence plans as bloc eyes independence from US

However, the government appears to be losing the battle for people's minds, with several opinion polls reporting that more than 60 percent of people polled believe the legal crackdown on CHP is politically motivated.

Anger against the government also continues to grow over 40 percent inflation.

Sezin Oney, an analyst for the independent Poltiyol news outlet, fears a political showdown is looming. "Turkish democracy is on its deathbed, actually. Erdogan envisions a political stage where we don't have a really challenging opposition. [Arrests] will escalate and escalate. They will go as far as they can until they reach their target."

While Erdogan remains in a strong position, the opposition is still a threat to the president. "He does have most of the cards," said Oney, "but he doesn't have the support of the public in general. So, at the end of the day, at one point it will be the people versus Erdogan."

"What matters is where the security forces stand," he added, "When it comes to a point when the people take to the streets en masse, will the security bureaucracy go against their own people?"

Neither the CHP nor Erdogan are showing any signs of capitulating, with protests expected to continue and likely to intensify in September, coinciding with the reopening of universities and the return of people from summer holidays. Court cases against the CHP are also scheduled to resume then.

With both sides insisting they are fighting for the future of their country, it could well be a fight that leaves only one side standing.