DEVELOPERS behind a controversial housing block that was refused planning permission after a mistake by government officers have taken their fight for approval to the High Court. In a test case which will be keenly watched by other developers, the court heard Super Mate Ltd first applied to build a 27-storey residential block in U Lam Terrace, Sheung Wan, in February last year. Michael Thomas QC, counsel for Super Mate, said planning bosses had refused permission on the grounds that the building was too tall for the surroundings. But they eventually admitted they had acted outside their powers when the case came before the Buildings Appeal Tribunal in November. The developers re-submitted plans immediately but were surprised to find them turned down again. This time planners said they contravened the draft Outline Zoning Plan which had been introduced just three weeks earlier. But Mr Thomas argued that if a public authority made a ''boo boo'' it was unfair to apply new laws when rectifying their mistakes if they had not been in force at the time the original error was made. The hearing before Mr Justice Mayo will finish today.