ANKARA, March 28 () – Turkish banks have started providing lira to the London swap market, an official said on Thursday, a day after banks were told to withhold lira liquidity from the key foreign market until Sunday’s local elections. On Wednesday, the London overnight swap rate surged as high as 1,200 percent in what was a stop-gap measure to bolster the lira. That was by far its highest on record, and economists said that level was no longer based on actual trading. The London overnight and weekly swap rates fell as low as 50 percent on Thursday. (Reporting by Nevzat Devranoglu; Writing by Tuvan Gumrukcu)Our Standards:The Thomson Trust Principles.