His public career was marked by great independence and fidelity to principle. On 24 July 1663 he alone signed a protest against the bill "for the encouragement of trade", on the plea that owing to the free export of coin and bullion allowed by the act, and to the importation of foreign commodities being greater than the export of home goods, "it must necessarily follow ... that our silver will also be carried away into foreign parts and all trade fail for want of money." He especially disapproved of another clause in the same bill forbidding the importation of Irish cattle into England, a mischievous measure promoted by the Duke of Buckingham, and he opposed again the bill brought in with that object in January 1667, though without success. This same year his naval accounts were subjected to an examination in consequence of his indignant refusal to take part in the attack upon Ormonde; and he was suspended from his office in 1668, no charge, however, against him being substantiated. He took a prominent part in the dispute in 1671 between the two Houses concerning the right of the Lords to amend money bills, and wrote a learned pamphlet on the question entitled "The Privileges of the House of Lords and Commons" (1702), in which the right of the Lords was asserted. In April 1673, he was appointed Lord Privy Seal, and was disappointed at not obtaining the Great Seal the same year on the removal of Lord Shaftesbury.