From Longman Dictionary of Contemporary Englishtrue-blueˌtrue-ˈblue adjective 1 British English informalPPG believing completely in the ideas of the British Conservative Party a true-blue Tory2 American EnglishFAITHFUL completely loyal to a person or idea a true-blue friend
Examples from the Corpus
true-blue• However, his opponents are convinced that even in true-blue East Hampshire Tory popularity is on the wane.• The predicted backlash from true-blue supporters has never materialised. 