Penderecki's 'St Luke Passion' is not usually considered a sonoristic work. In the United Kingdom, however, firsthand experience of truly sonoristic pieces was limited and St Luke was the first notable experience of the style for many British audiences. After two performances in 1967 London's critical community divided, a pattern that would mirror international opinion in the following decades. The work's detractors labelled it an unthinking collection of sound effects. Its defenders attempted to negate these accusations by distancing the work from the Polish school and stressing its conventional methods of construction, passing over its extravagant soundworld to focus on recognisable models such as serialism, strict counterpoint, organic development and underlying tonalities. Negatively or positively, sonorism was regarded in the work as a colouristic device, a means by which modernistic means were domesticated to word-painting or dramatic embellishment. Both instances, this paper will argue, did a disservice to the work as an example of Polish political defiance, which was suppressed by either the criticism of its sonoristic technique as mere sound effects or its reduction to familiar Western European designs. Through a combination of reception history and score analysis, this article examines the impact of St Luke in the formation of a British interpretation of sonorism, and compares this to a new reading of the work that draws attention to its use of sonoristic means in support of a political-theological programme, restoring its forgotten political power and arriving at a richer understanding of Penderecki's sonoristic method.