The latest quarterly APPC register, published this week, reveals agency public affairs clients between 1 June and 31 August.
It is the first such register to emerge since David Cameron and Nick Clegg agreed to from a coalition government on 11 May.
Edelman, Fleishman-Hillard and Connect Communications are among those to register a higher number of fee-paying clients compared with the previous quarter.
Edelman has increased public affairs client numbers from 48 to 52, Fleishman-Hillard from 41 to 44 and Connect from 47 to 52. Insight Public Affairs also saw a rise from 25 to 27, with Anchor Housing Trust among its new retained clients.
But several other agencies have registered a decrease in client numbers. Blue Rubicon, once viewed as an agency in the ascendancy, has seen the number of fee-paying clients dip from 17 to 16 in the latest register.
Weber Shandwick has seen a more substantial fall from 81 to 74 clients, while Grayling has registered a steep drop from 73 to 56 clients.
The records suggest that Four Communications has fared worst in recent months, with the number of fee- paying clients falling dramatically from 131 in the previous register to 89 in the new one.
However, a spokeswoman for the agency insisted this was merely due to housekeeping. She said: ‘A lot of the work we do as a public affairs consultancy is individual projects to support a planning application. If it looks like we will be retained by the same client for another project, we will keep them on as clients.
‘In this case, we have had a look at clients still registered on our books and removed those with whom we are not working on future projects.’
Four Communications group CEO Nan Williams insisted that the agency had actually seen the public affairs business pick up significantly since the election. She said: 'Our income for the last quarter was up by seven per cent - which is a pretty encouraging jump - from £335,218 to £358,123.'
The number of clients on the register does not necessarily indicate the health of an agency, as the register does not state whether clients are retainers or project-based.
Agencies not on the register include Bell Pottinger Public Affairs, TLG and DLA Piper.
This story has been amended since from the print version which incorrectly stated that Luther Pendragon was not on the APPC register. Luther Pendragon joined the APPC in May this year.