He participated in the opposition to Edward III and the court party, which grew in strength towards the end of the reign, taking the popular side and being prominent in the Good Parliament of 1376 among the lords who supported the Prince of Wales and opposed the Court Party and John of Gaunt. The Speaker of the House of Commons in this parliament was March's steward, Peter de la Mare, (1294-1387 of Little Hereford, Hereford), who firmly withstood John of Gaunt in stating the grievances of the Commons, in supporting the impeachment of several high court officials, and in procuring the banishment of the king's mistress, Alice Perrers. March was a member of the administrative council appointed by the same parliament after the death of Edward, the Black Prince to attend the king and advise him in all public affairs.