Treasury in the last year for which the accounts are complete.[123:1] This brings us to another important question, that of the financial control of the Treasury over the other branches of the administration. [Sidenote: Treasury Control over Other Departments.] [Sidenote: Control over Estimates.] There has been a great deal of discussion about Treasury control over the receipt and expenditure of public money. In the case of the receipts it is a simple matter, for the financial control over the Post Office has already been described, and the other great revenue departments are, as will shortly be explained, virtually subordinate to the Treasury. The question of control over expenditure is far more complicated. Committees of the House of Commons have, at different times, collected evidence on the subject,[123:2] but the statements made have often been vague, and tend to confuse the control of the Treasury over the estimates, with its control over expenditure after the appropriations have been voted by Parliament. The control over the estimates has been discussed in the preceding chapter. It is only necessary here to repeat that such a control is by no means absolute, because any important question of expenditure becomes a question of policy to be decided, in case of disagreement, by the Prime Minister or the cabinet; and to point out that the departments supported by their political chiefs are usually too strong for the Treasury to resist.[123:3] [Sidenote: Control over Expenditure.] It might be supposed that after the appropriations had been voted the departments would be free in expending them, subject only to their responsibility to Parliament; but this is not altogether true. In the first place a statute sometimes requires that the expenses of a department shall be sanctioned by the Treasury.[124:1] Then it is not infrequently provided that the salaries shall be fixed by the Treasury, or that alterations in the establishment shall require its consent. Moreover, the salaries of certain grades of clerks are regulated by Orders in Council,[124:2] which are changed only on the advice of the Treasury. Apart, however, from statutes and Orders in Council there is a general customary principle forbidding any increase in the civil establishment of a department,--that is, any increase in the number or salary of permanent officials,--without the approval of the Treasury; and this although the appropriations would not be exceeded.[124:3] [Sidenote: Transfer of a Surplus.]