Interviewed on this morning’s BBC Radio4 ‘Today’ programme about the election of John Bercow as the new Speaker of the House of Commons, the MP Nadine Dorries (Conservative, Mid Bedfordshire) claimed that this was a vindictive act on behalf of the Labour Party. I wonder who committed it, then. I think she meant to say ‘on the part of’ the Labour Party.
‘On behalf of’ is increasingly used where ‘on the part of ‘ would be better. In fact, the traditional meanings of the two phrases are diametrically opposed: ‘on behalf of’ means acting in someone else’s interests, while ‘on the part of’ means made or done by the person or group mentioned.
The two expressions could be replaced by the simple ‘for’ (on behalf of) or ‘by’ (on the part of), but these carry less ‘weight’ than the longer phrases and so might more easily be missed.
If ‘on the part of’ disappears from the language, we shall have lost a useful way of distinguishing between what we do and what is done for us.