Peter Gluckman offer
ten points of advice at Nature for those interested in advising government regarding science policy. Amongst the ten, this one is probably most critical:
Distinguish science for policy from policy for science. Science
advising is distinct from the role of administering the system of public
funding for science. There is potential for perceived conflict of
interest and consequent loss of influence if the science adviser has
both roles. There is a risk that the adviser comes to be perceived as a
lobbyist for resources [Emphasis mine].