David Hunter (Scottish Government) said that the policy had been presented as being aimed at fat cats. But staff on modest salaries under £30,000 – but with long service and an entitlement to an unreduced pension – will also be badly affected.
Many other middle earners in between those two groups would also be hit, he added.
The motion described the cap as being part of an on-going process of dismembering the terms and conditions that were among the key reasons members became public servants in the first place.
Hunter said it would be up to the devolved administrations to decide if and how the cap would be introduced in Scotland, Wales and Northern Ireland. This was therefore an opportunity to make a strong case against it in the regions.
The motion, which was backed by the executive, was passed unanimously.