The Plowden committee on the control of public expenditure has been described as a milestone in the modernization of postwar British government. Certainly it effected major changes in both the Treasury's structure and personnel and, by securing the establishment of the public expenditure survey committee, gave subsequent governments the opportunity to plan public expenditure rationally in relation to prospective resources. Ultimately, however, the committee was a failure. The civil service was re-examined by the Fulton committee within five years and public expenditure soon escalated out of control. The Plowden committee thus represented a major lost opportunity. The time had been ripe for a fundamental political and administrative adjustment to the needs of the extended postwar state; but the committee failed to build the necessary political, parliamentary or public support for its recommendations. The reason for failure was its restricted nature as an internal enquiry with largely ineffectual ‘outside’ members, which enabled vested Treasury interests increasingly to dictate its deliberations. A more open enquiry would have stimulated and brought the best out of the ‘modernizers’ within the Treasury. The committee, therefore, proved to be not an administrative milestone but a prime example of how British institutions, under the guise of reform, have traditionally deflected criticism, truncated discussion and thereby stifled the fundamental reforms required to halt Britain's decline. In relation to welfare policy, the committee failed to examine the relative efficiency of collective provision in given policy areas, opposed contracyclical demand management and covertly sought to cap welfare expenditure. In short, it accepted the electoral necessity but not the legitimacy of the welfare state.