By Maria Ward-Brennan City headquartered law firm Withers is prepping an international arbitration against the Swiss government for its role in the merger of Credit Suisse and UBS. The law firm is looking to take action on behalf of Hong Kong AT1 bondholders on the legal basis that Switzerland breached its obligations under its bilateral investment treaty with Hong Kong. The firm is currently working to sign eligible bondholders up to its group action, with a deadline of 15 June. This action is being led by Singapore-based partner Shaun Leong and London-based partner Robert Kovacs, It has been…