Dr William Cheng, part-owner of Tai Ka Lok in Gerrard Street, says his restaurant will have to close if the landlord, Shaftesbury, succeeds in tripling his rent from £63,000 to £178,000 a year. The case will be going to arbitration next month and could trigger a damaging domino effect if the landlord wins. Another 50 restaurants and shops in Chinatown face similar disputes.