Turmoil in global markets as Spanish bank borrowing from ECB doubles Spain's Ibex stock market plunged 3.6pc, with bank stocks leading the fall. The nation's benchmark 10-year bond yields soared past 6pc, heading deep into the danger zone that experts say is not sustainable without external support. Meanwhile, the cost of credit default swaps hit a record high of 500 basis points, meaning it costs £500,000 a year to insure £10m of Spanish debt over five years. This compares with around £70,000 for German debt. The alarm came just the day after Mariano Rajoy's government secured parliamentary approval of Brussels' budget stability law that binds Spain to achieving a balanced budget by 2020. Michael Derks, chief strategist at Forex, said bondholders "suspect that, despite his best endeavours, Rajoy will be unable to prevent Spain also falling into the hands of international creditors." Klaas Knot, the president of the Dutch central bank and ECB board member, said: "I don't think we're heading towards the edge of a cliff. Asked if the ECB would re-start its bond buying programme to pull down the bond yields of Spain and Italy, he said: "The instrument has not been used a long time but it still exists. Economists warned that bond buying would cause deep divisions within the ECB and opposition from Germany outside it. Equally a "third round of LTRO would look desperate and would probably also fail to mollify investors," said Michael Derks. Next weekend the International Monetary Fund (IMF) is meeting in Washington. Earlier this week Christine Lagarde made a plea for the G20 to approve more funds so the IMF can act as a "global firewall" against the advancing debt crisis.