The ABPI has gone public with a statement saying that it served notice on Luther Pendragon in December after learning the agency had decided to take on the account.
The ABPI said it subsequently appointed MHP Health Mandate to provide public affairs support.
The move appears to have been sparked by the latest APPC register listing Phillip Morris as a Luther Pendragon client.
The latest APPC register covers the period 1 September to 30 November. According the register, the agency began working with the tobacco giant last summer during the period 1 June to 31 August.
Previously Phillip Morris had received public affairs advice from Gardant Communications.
Luther Pendragon was awarded a two-year contract to advise the ABPI on building better relationships with politicians, patient organisations and the NHS in February last year.
Luther Pendragon declined to comment.