Hopefully this debate will be resolved soon by ACAS
I think you may be confused about what ACAS actually do, it is not their role to resolve anything, that is for BA and BASSA. This isn't my "personal opinion", it's a fact, see the quote below from the ACAS website (
www.acas.org.uk)
What is conciliation?
It is a voluntary process of discussion and negotiation by which Acas helps parties in dispute to reach their own agreement. Acas conciliators have no power to impose, or even recommend, settlements.