From Longman Dictionary of Contemporary Englishstalwart supporter/ally etcstalwart supporter/ally etcFAITHFULa very loyal and strong supporter etc → stalwart
Examples from the Corpus
stalwart supporter/ally etc• Few people could have made a less favorable impression or turned out to be such a stalwart ally.• They are her stalwart supporters in a dosed, oppressive world.