The Chairman of Ways and Means/Deputy Speakers
The positions of Deputy Speaker and Chairman of Ways and Means developed separately until they were combined in the mid-19th century. The terms are now used interchangeably.
The Chairman of Ways and Means is the principal Deputy Speaker and began to formally deputise for the Speaker from 1853. The incumbent may exercise all the authority of the Speaker, and also has distinct responsibilities of his own.
The office of the Chairman of Ways and Means arose out of the traditionally ambivalent position of Speakers vis-à-vis the Commons and the Sovereign.
Until at least the 18th century, Speakers were placed in an increasingly untenable and dangerous position: meant to represent the House's interests to the King on the one hand, and the King's interests to the House on the other.
After the Restoration, in the late 17th century, the Commons resolved that whenever it was to consider the financial demands of the King, it would need to resolve itself into a committee of the whole House, chaired by its ‘own man', rather than the Speaker, who was seen as the King's spy.
Hence the office was born, and its first occupant was Richard Hampden, a Whig politician. The practice of electing the same MP to be Chairman in successive sessions of Parliament was quickly established, and the position became paid from 1800.
The Commons' desire to act freely and independently and without ‘spies' when it came to considering issues of supply and budget endured and could be seen in the House's continuing arrangements.
Between 1641 and 1967, the Chairman of Ways and Means presided over the Committee of Ways and Means, which initiated proposals for raising taxation.
Since 1967 when the Committee was abolished, all fiscal matters, including taxation, have resided with the Chancellor of the Exchequer.
Moreover, it is the custom for the Chairman to take the chair during the debate on the Chancellor's Budget, even though there is nothing preventing the Speaker from presiding over the Budget debate (and it has happened in practice). The financial measures contained in the Chancellor's Budget are brought in on Ways and Means Resolutions.