Related:
http://www.delgazette.com/news/opinion-opinion_columns/153224190/Happy-birthday-Magna-Carta
“What few people realize, however, is that the original charter was in effect for only 10 weeks. Having been backed into a corner, King John wrote to the pope, stating that he was forced into signing it and offering to give in to all of the pope’s demands if the pope would side with him on rescinding the Magna Carta. Pope Innocent III was more than willing to do so and, in August 1215, issued a papal bull declaring “utterly canceling and making void” all of its provisions.”
“To no one will we sell, to no one deny or delay right or justice.”
— Magna Carta; June 10, 1215
“[We] do utterly reprobate and condemn this agreement and under ban of anathema we command that neither the King shall presume to observe it nor the Barons and their accomplices to require its observation.”
— Papal bull; Aug. 24, 1215
Technically true as far as it goes but from John on English kings traditionally have asserted their recognition of magna carta upon assumption of the throne, at least through the Plantagenet dynasty. It was only temporarily set aside but when the king needed his barons to provide men and money it was brought back into play and has been ever since.