I then looked at what was available on ResearchGate. These are quite old now:
Kacmar, K. M., & Ferris, G. R. (1991). Perceptions of organizational politics scale (POPS): Development and construct validation. Educational and Psychological measurement, 51(1), 193-205.
Article Perceptions of Organizational Politics Scale (POPS): Develop...
Ferris, G. R., & Kacmar, K. M. (1992). Perceptions of organizational politics. Journal of management, 18(1), 93-116.
Article Perceptions of Organizational Politics
Kacmar, K. M., & Carlson, D. S. (1997). Further validation of the perceptions of politics scale (POPS): A multiple sample investigation. Journal of management, 23(5), 627-658.
Article Perceptions of Organizational Politics Scale (POPS): Develop...
Pankratz, M., Hallfors, D., & Cho, H. (2002). Measuring perceptions of innovation adoption: the diffusion of a federal drug prevention policy. Health Education Research, 17(3), 315-326.
Article Measuring perceptions of innovation adoption: The diffusion ...
Bouckenooghe, D., Devos, G., & Van den Broeck, H. (2009). Organizational change questionnaire–climate of change, processes, and readiness: Development of a new instrument. The Journal of psychology, 143(6), 559-599.
Article Organizational Change Questionnaire–Climate of Change, Proce...
You can use questionnaire, make a well planned survey to achieve your goal. You can find an example in this article https://www.researchgate.net/publication/339352369_Bridging_the_gap_of_perception_is_the_only_way_to_align_soil_protection_actions
By conducting survey about the new policy. Lots of market research companies are doing that. Present trends is to conduct the survey using the web/e- platforms
Survey and opinion polls are OK but focus-groups, projective techniques and synetics are very useful, too, because they are more adequate to approach the specific target-groups and beneficiaries of the respective new policy and explore their true attitudes and beliefs
I suggest you consider an acceptance model. You can use your own model or customise a previously validated model to suit the intent of your study. You noted in your enquiry that you wanted to measure perceptions. For this, you must use multivariate analysis. That is to say, first you specify a measurement theory and you validate it by means of exploratory and confirnatory factor analysis. Then you assess the structural model for you to be able to inspect the cause- effect relationships in your model, which is also a prerequisite for measuring perceptions.