He is a former ESB worker and trade union representative.[3] He was elected to Wexford County Council in 2014 for the Enniscorthy local electoral area, serving for five years before losing his seat. He previously contested the 2016 general election in the Wexford constituency, but narrowly missed out on the last seat by a margin of 52 votes.[4] Mythen also contested the 2019 Wexford by-election, receiving 4,125 votes (10.3%) and being eliminated on the third count.