The Fire Brigade Union's Welsh committee agreed to give Marc Jones £500 towards his election campaign after many years of cooperation with the trade union activist.
Mr Jones, who is also a county councillor for the Whitegate ward, worked voluntarily for the FBU Wales during the 2003 strike and helped edit and produce the union's weekly strike bulletin.
Mr Jones, a former journalist, said he was delighted with the donation:
"I've worked with the FBU locally and nationally for almost a decade, promoting trade union issues and concerns. This was most evident during the bitter firefighters' strike, when the FBU took on John Prescott and the Labour government. There was huge public support for the firefighters' cause, which was evident in the money we raised on the streets of Wrexham, but Labour behaved like the worst kind of employer and tried to smash the union into submission.
"In my role as a journalist I've also written about fire safety issues of concern to the FBU and continue to work with the local FBU branch secretary Mike Davies, who was instrumental in helping me to get this very welcome donation."
"It's a huge boost to Plaid's coffers locally as we are entirely reliant on members' donations and fundraising efforts for our campaigning. Unlike the big London parties, we don't get funding from millionaires and tax exiles so every penny from respected organisations such as the FBU is a great boost to supplement our own efforts.
"It's also an important reminder to trade unionists that Plaid is a party for workers in Wales. We are committed to defending public services such as the fire service as we go into the Assembly elections on May 5."