After shutting down the center of Athens and parts of Greece yesterday during protests over structural reforms, unionists said they were determined to prevent the government from tampering with social security and pensions. «Stop playing around with social security funds. Do not burden IKA (the main state fund) with the debts of bankers and do not abolish the eight-hour working day,» said Christos Polyzogopoulos, the head of the country’s largest umbrella union, GSEE, which had called a general strike yesterday in support of bank employees who oppose government plans to reform their pension schemes. In its bill, the government has proposed registering all new bank workers with IKA by 2008. The bank employees’ union OTOE said yesterday that it would extend its strike, currently in its third week, until Thursday, when Parliament is expected to vote on the bill.