 That year he also began to work with Muhammad al-Badr in resisting Egyptian efforts to install an ally as President of North Yemen where he became the principal military advisor to the Royalist forces.He persuaded the Foreign Office not to recognize the Communist-backed government in the country; an accomplishment described by McLean's biographer Xan Fielding as his "crowning achievement".In June 1964 McLean introduced a Private Members Bill aimed at protecting some paper mills, shipbuilding and cotton firms which had received government grants from nationalization.