Dame Mary intends to take early retirement in the spring, the Treasury told Accountancy Age.

Insiders have tipped Mal Singh, head of the finance professionalism team and Dame Mary’s second-in-command, as a likely successor.

A Treasury spokesman said she would be leaving ‘some time in the spring’, adding: ‘She agreed [her early retirement] with the home secretary in 2006. The search will begin at some point in the future to find a suitable replacement. ‘

The news of Dame Mary’s departure comes as other public finance leaders called for civil service FD wages to be brought into line with their private sector counterparts.

The Treasury’s Financial Skills Advisory Panel, headed by CIPFA chief executive Steve Freer, said: ‘[FD roles] should be supported by packages which compete with the external market. While many people choose to work in the sector for reasons other than financial gain, competitive remuneration remains an important unresolved difficulty.‘