Unions representing postal, utility and delivery staff have long argued for laws to be extended to cover attacks in dog owners' homes, saying this is a "major loophole" in the law and their workers - as well as others - need more protection.
The war of words flared as Royal Mail boss Adam Crozier rubbished the main postal workers' union's suggestion that the firm treats its staff as "slaves".
The dispute was started by more than 200 postal workers at the city's Tomb Street depot following difficulties between staff and management over disciplinary procedures and other issues in the north Belfast section.