Before being brought to the place of execution, Mayne was offered his life in return for a renunciation of his religion and an acknowledgment of the supremacy of the queen as head of the church. Declining both offers, he kissed a copy of the Bible, declaring that, “the queen neither ever was, nor is, nor ever shall be, the head of the church of England”.
A special, high gibbet was erected in the marketplace at Launceston, and Mayne was executed there on 29 November 1577. He was not allowed to speak to the crowd, but only to say his prayers quietly. Just as he was about to be hanged, he refused to implicate his co-religionists. It is unclear if he died on the gibbet. One source states that he was cut down alive, but in falling struck his head against the butcher’s scaffold. In any case, he was unconscious during the disembowelling.