Vermigli became deeply involved in English church politics. In 1550, he and Martin Bucer provided recommendations to Cranmer for additional changes to the "Book of Common Prayer" Eucharistic liturgy. Vermigli supported the church's position in the vestarian controversy, over whether bishop John Hooper should be forced to wear a surplice. Vermigli agreed with Hooper's desire to rid the church of elaborate garments, but he did not believe they were strictly prohibited. He advised Hooper to respect the authority of his superiors. Vermigli was probably instrumental in convincing Hooper to drop his opposition in February 1551. In October 1551 he participated in a commission to rewrite the canon law of England. In the Winter he assisted in the writing of a draft set of such laws, which was published by John Foxe as "Reformatio legum ecclesiasticarum" in 1552.