[cycomanic]

I can't give you direct links, but I know that large scientific/engineering organisations have not been pushing for free open access. For example the IEEE has been part of an open letter (which included Elsivier) lobbying against Plan S. These organisations derive a lot of their money from publishing, so while many (most) of the members are strongly in favor of OA, the buerocratics in the organisations often are not. Which gives mixed messages to politicians.

On top of that I believe that non-scientific publishers have also been part of the lobby campaign as they see OA as weakening copyright.