In the 1990s he briefly served as a municipal councillor for the latter and was co-founder of the nationalist Dutch Block.

In the 2000s and later he was an activist, writer and video maker and he was involved with and collaborated with groups and individuals, some of which were white nationalists.

[12][13] Since then he is active for several "eurocentrist" (European identity advocating) groups, wrote articles for various magazines and websites and made a video interview series with far-right figures such as David Duke, Horst Mahler and Guillaume Faye.

[17] He was active in board of the Reinwater foundation (an activist group for protecting the river Rhine)[18] until 11 July 1979,[19] he was active as representative of Milieudefensie to the European Environmental Bureau in Brussels[20] and he was president of the Ecological Movement in the Netherlands until 12 February 1983.

[24] In the July–September 2010 issue no 4 of Ab Aeterno (Journal of the Academy of Social & Political Research) Vierling published an article about the Netherlands in world context entitled The Netherlands, a Failed State in a Failed Continent.