Workers at two branches of the American diner chain TGI Fridays are holding walk-outs over changes they say will cost them hundreds of pounds a month. The firm has introduced a new pay policy, which redistributes customer tips from waiters to kitchen staff. The 24-hour strike will affect branches in Milton Keynes and Covent Garden.The Unite union has forecast a "summer of disruption" by unhappy employees. The firm said it pays its staff fairly and is working to find a resolution. Flagging consumer spending on casual dining combined with rises in the minimum wage are squeezing profits at mid-market restaurants like TGI Fridays. In February the chain introduced a system that takes 40% of tips paid by customers on credit and debit cards for redistribution to back-of-house staff. Unite said the aim was to reduce staff turnover in kitchens by giving them a pay rise without increasing costs. But the union said it would cost waiting staff on the minimum wage up to £250 a month in lost income.