Hearne lived in Taff Ely, where he was the Communist Party candidate for Gilfach Goch Ward in 1976, a ward he had previously stood in. The branch secretary of the Britannic Lodge of the South Wales National Union of Mineworkers, he had earned a fierce reputation as a fighter for the rights of miners’ widows to have concessionary coal.
Hearne was also the Vice-Chair of both the local RugbyFootball Club Committee and a local committee member of the Workingmen's Hall. He was also chair of the Gilfach Goch Community Association’s action committee on the occasion of its successful 1968 campaign against health cuts in the valley. He was married with one son. Mervyn is pictured here in his election address.