The Alliance Party is to boycott the Northern Forum's parades committee following the rejection by the committee of a submission from the Garvaghy Road Residents' Association.
Forum member Mr Stephen McBride of Alliance criticised the committee for refusing to consider the Garvaghy residents' submission.
However, the committee chairman, Mr Cedric Wilson of the Ulster Unionist Party, said it was "the final nail in the coffin of the peace process".