The APPC's Code of Conduct compels our member organisations not to hire any sitting MP or peer (not to mention MEPs or members of devolved assemblies), and with very good reason.
Of course MPs should be able to undertake paid work outside of their day job - most of us have no problem with that.
Those who do declare it publicly on the register of interests.
Many former MPs also take up posts within our industry, something that is perfectly legitimate given their hands-on expertise in policy-making.
However, it's hard to argue that an MP working for a lobbying agency is not engaged in lobbying, either directly or indirectly.
It is one thing sitting on the board of an organisation that may, from time to time, lobby.
It's another thing completely to work for a lobbying agency, whose raison d'être is exclusively to lobby.
The real, or perceived, conflict of interest when an MP takes up a post for a lobbying agency chips away both at the credibility of our elected politicians and the wider lobbying industry.
Lobbyists and MPs should have clear boundaries; a principle enshrined in our code.
It is for this precise reason that the APPC is also so strongly opposed to lobbyists holding parliamentary passes.
The good news is that while the creation of the new statutory register might not include plans for an accompanying code of conduct, the APPC's register and code will sit in parallel with the new register, providing the transparency and upholding best practice by which we believe all lobbying agencies should abide.
Iain Anderson is chairman of the Association of Professional Political Consultants (APPC)