You are at a parliamentary reception and meet the researcher of an MP that your client has wanted to meet for a while to discuss a specific issue.

When speaking to a researcher, you should introduce yourself as a political consultant, naming your client and their interests.  You may talk to the researcher about the specific issue as long you make it clear that you are doing so on behalf of your named client who has a very clear position on the issue.

Clause 4 of the APPC Code of Conduct states

In making representations to the institutions of government, political practitioners must be open in disclosing the identity of their clients and must not misrepresent their interests