P.R. Irwin (played by Dermot Crowley) is the main antagonist of Mrs. Brown's Boy's D'Movie. Irwin was in arrangement with a ruthless Russian businessman who was closing down all the market stalls on Moore Street so he could put up a shopping centre on the site, and he has a trio of Russian thugs doing his dirty work. Irwin then targeted Agnes Brown's stall, and was determined to go to any lengths he had to to get what he wanted, even using Agnes' confession that she briefly placed her children into care after her husband died and continued to collect their child support money during that time against her. But Irwin's attempts to get Agnes to sell her stall would ultimately end in failure; although Irwin destroyed the original receipt which would have proven that Agnes' grandmother had paid off the debt, he did not count on their being a receipt in Braille. Buster Brady, accompanied by Mr. Wang and a troop of blind ninjas found the receipt and got it to the courthouse in time.

Following the verdict, Irwin tries to make his escape, but the furious Russians intercept him and take him away, most likely to punish him for his failure.