Harper remained active in constitutional issues. He was a prominent opponent of the Calgary Declaration on national unity in late 1997, describing it as an "appeasement strategy" against Quebec nationalism. He called for federalist politicians to reject this strategy, and approach future constitutional talks from the position that "Quebec separatists are the problem and they need to be fixed". In late 1999, Harper called for the federal government to establish clear rules for any future Quebec referendum on sovereignty. Some have identified Harper's views as an influence on the Chrétien government's "Clarity Act".