The new group HOWL (Hay-On-Wye Library - for the HOWLs of protest!) has shared the email of the county councillor responsible for library provision in Powys.
It is email@example.com
and his address is:
Councillor Graham Brown, Deputy Leader/Cabinet Portfolio Holder, Member Support, Powys County Hall, Spa Road East, Llandrindod Wells, Powys LD1 5LG
He's the one to write to with any comments, for Hay and any of the other libraries under threat.
And it's probably best to keep copies of any communications, so they can be used again in the official consultation process.