IN its strongest attack so far, the Radio Television Hongkong staff union yesterday accused the Government of yet again breaking its promise to resolve the issue of the broadcaster's future. This followed an announcement by the Secretary for Recreation and Culture, Mr James So Yiu-cho, that the question of corporatisation would be given low priority by the branch this year. Mr So said he did not want to turn what is ''basically an internal management restructuring exercise into a high profile political issue''. The RTHK Programme Staff Union accused Mr So of indicating he might shelve the exercise, and is seeking an urgent meeting to clarify his position. ''The corporatisation exercise has been littered with broken promises,'' a union statement said. ''The latest excuse from Mr So, that the Recreation and Culture Branch has more urgent matters to tackle, is an insult to RTHK staff, who have now been waiting eight years for a decision,'' it said. Union secretary Mr Cliff Bale accused Mr So of back tracking and being vague and ambiguous. He described RTHK staff as extremely angry over the latest comments. ''Mr So said late last year that something would be put to the Executive Council early this year, now we are being told there will be further delays,'' said Mr Bale. ''Over the past two years we have been told corporatisation will happen, but his series of promises have never materialised. ''That's why we want to meet with him - he owes us a clarification,'' Mr Bale said. RTHK corporatisation was first recommended in the 1985 Broadcasting Review, but the plan has since slipped down the Government agenda and has been rejected by China. Mr So was not available for comments last night. But earlier at a press conference, he said he did not want to make a pledge over RTHK corporatisation which he may not be able to keep. He only promised to keep the subject ''under review'' in the course of the year. While denying that the issue was being dropped, he said there was no timetable for corporatisation. It was the issuing of Hongkong's pay-TV licence which Mr So said was the branch's priority for 1993. Mr So said that a draft of the pay-TV licence, the terms of which were now being discussed with lone bidder Wharf, will be ready after Lunar New Year. The conditions will then be discussed in full with China representatives through the Joint Liaison Group. ''I am very confident we will get a service up and running by October this year,'' said Mr So, referring to the branch's own deadline. Meanwhile, the Broadcasting Authority yesterday announced a series of relaxations to its codes of practice which it believes will be welcomed by both viewers and broadcasters. Live telecast of sporting events need no longer be interrupted at crucial moments to comply with the 10-minute minimum programming rule. This will also allow advertisements to be placed in films at ''natural breaks'' rather than when the 10-minute rule dictated. Broadcasters have also been given a freer hand to edit films at their own discretion. In yesterday's South China Morning Post , a picture was incorrectly captioned as Mr James To Kun-sun. It should have read Mr James So Yiu-cho.