Answer:
reactive devaluation.
Step-by-step explanation:
Reactive devaluation is a term used to describe a situation whereby an individual or a group of people devalues a proposal that is made by a party who they perceive in a bad light or do not trust. In this case, if the proposal comes from another party that they agree with or trust, they would likely accept the proposal. Reactive devaluation often stems out of distrust or the tendency of a party to view the other party making a proposal in a negative way.
The case cited in the question is an example of reactive devaluation.