“MUCH talk cannot be free of lies, much wealth cannot be free of illicit gain.” This old Turkish adage was tweeted by a former culture minister, Ertugrul Gunay, just as the prime minister, Recep Tayyip Erdogan, was addressing members of his Justice and Development (AK) party in the parliament on January 28th. The message is starting to reflect the public view of the embattled government. More than a month after a three-pronged corruption investigation implicating ministers, close business allies of the prime minister and, even more damningly, his family, the scandal shows no sign of abating.

Mr Erdogan is trying hard to paint it all as a plot devised by Israel, America, their financiers and the foreign media. He says their plans to destroy his government and Turkey are being carried out by disciples of his former ally and “bogus prophet”, Fethullah Gulen, a Pennsylvania-based Sunni Muslim cleric, who are embedded in the judiciary and the police. But to many Turks this story is beginning to sound hollow.

The reshuffling of thousands of supposedly Gulen-affiliated police, judges and prosecutors because they are part of an attempted “coup” has merely reinforced suspicions of a cover-up. Kemal Kilicdaroglu, the leader of the main opposition, the secular Republican People’s Party (CHP), is having a field day. “Was $99,999,990 transferred into Turgev’s account?” he asked in parliament, referring to a charity set up by Mr Erdogan’s younger son, Bilal.

Complaints about Mr Erdogan’s children, whose alleged phone calls with a developer were taped as part of the corruption inquiry, are said to include helping to secure the re-zoning of a protected historical Aegean site to allow the construction of luxury villas. Access to several Turkish websites and to SoundCloud, an online audio platform that hosted the recordings, has been blocked. But new sites offering streams of other evidence from prosecutors keep popping up.

Mr Erdogan’s response has been to dig an even deeper hole. He called Muharrem Yilmaz, chairman of Turkey’s industrialists’ lobby, “a traitor” for saying that, if the rule of law were not observed, foreign investors would shun Turkey. He has threatened Frank Ricciardone, the American ambassador, with expulsion. Chuck Hagel, America’s defence secretary, has postponed a planned visit to Turkey without offering a clear explanation. Mr Erdogan is also continuing his anti-Semitic tirades against Western media, including The Economist. “We know who owns them,” he bellowed this week.

By contrast, in interviews with the Wall Street Journal and the BBC, Mr Gulen has shunned inflammatory language, portraying himself as a selfless democrat concerned by Mr Erdogan’s lurch towards authoritarianism. The damage inflicted by a televised sermon in which Mr Gulen rained curses on the government, and by a leaked conversation with a businessman in which he discusses a tender for an oil refinery in Uganda with bizarre references to pineapples, have been offset by Mr Erdogan’s unabated diatribes against his flock. In a bid to regain the moral high ground, the Gulenists are reported to have stopped leaking secretly filmed videos exposing the bedroom antics of their foes.

Not surprisingly, Mr Erdogan’s erratic behaviour has taken its toll on investors who were already nervous about several emerging markets (see article). The Turkish lira has shed 13% against the dollar in just six weeks. Ignoring Mr Erdogan’s vociferous and repeated attacks on what he calls the “interest-rate lobby”, the Central Bank announced on January 28th, after an emergency meeting, that it was doubling the weekly repo rate from 4.5% to 10%. The markets heaved a sigh of relief and the lira and the Istanbul Stock Exchange began to recover—but the currency slid back again later.

Under all this pressure, Mr Erdogan’s once unassailable popularity may be starting to melt. Should the prime minister’s ranting persist, the voters may choose to say “enough”. Recent opinion polls suggest that AK might lose Istanbul to the CHP in the local elections on March 30th. And the outlook for the presidential election this summer is also uncertain.

Correction: This article initially said that SoundCloud had "posted" the recordings of Mr Erdogan's children's alleged phone calls. In fact it had merely hosted them. Sorry.