Should researchers disclose their political interests in publications?

Scenario: A researcher, who is also a member of the political party A, investigated the impact (e.g. on public health) of specific actions or policies (e.g. strikes or health expenditure cuts) belonging to the rival party B.

Assuming that the research motivation is scientifically justified, the methodology is sound, the results are "unbiased" and reproducible, and support was only received from an independent body (e.g. a research council), should the researcher disclose his/her political motivation in the publication?