Turkey’s Erdogan is under pressure as three cabinet members quit Turkey’s corruption crisis deepened on Wednesday as three cabinet ministers close to Prime Minister Recep Tayyip Erdogan tendered their resignations – among them economy minister Zafer Caglayan and interior minister Muammer Guler, both of whose sons are in prison awaiting trial on corruption charges. As interior minister and head of the police force, Mr Guler was particularly vulnerable as he was ultimately responsible for investigating his own son. Police raids more than a week ago were prompted by what has been revealed as a two-year investigation into bribery, corruption and gold smuggling. Mr Guler’s son, Baris, was discovered with a series of strong boxes in his home as well as a counting machine to keep track of large quantities of cash. Those responsible for conducting the raids have been removed from their posts for conducting the operation without informing their superiors. However, it is the resignation of the third cabinet member, urbanisation and environment minister Erdogan Bayraktar, that may prove most damaging. Mr Bayraktar, a political ally of the prime minister since Mr Erdogan became mayor of Istanbul in 1994, made clear he would not go quietly. He said he was under pressure to resign and, furthermore, to issue a statement that would not put pressure on the prime minister. He added that everything he had done had been with Mr Erdogan’s knowledge. "I declare my resignation from parliament, and as a minister," Mr Bayraktar said. "However, I also believe that to make the people more comfortable, the prime minister should also resign." Mr Bayraktar is not the only one of Mr Erdogan’s erstwhile political confidants to have sparred publicly with him in recent days. Analysts say the corruption charges represent an escalation in the animosity between Mr Erdogan and his former ally, the septuagenarian Islamic cleric Fethullah Gulen, who lives in self-imposed exile in Pennsylvania and has a large following in the Turkish police and judiciary. Prime Minister Erdogan again blamed foreign conspirators for colluding in his government’s problems. In a televised address, he accused "some media and special interests" of betraying the country. Borsa Istanbul, Turkey’s main stock exchange, fell 4.2 per cent on news of the resignations to its lowest level in more than four months. The latest twist in the crisis is likely to aggravate Turkey’s recent economic imbalances by putting further pressure on the Turkish lira. The central bank’s recent decision to defend the currency with reserves, rather than via higher interest rates, may limit inward flows. This, in turn, is likely to have a negative impact on reducing a current account deficit currently running at more than 8 per cent a year.