Lobbyists who hold parliamentary passes have been warned they risk harming perceptions of the industry.
The latest House of Lords register of interests has revealed that at least 57 people involved in the fields of public affairs and policy advice can freely enter the House. Of those, 34 work as lobbyists for charities.
BP director of UK government affairs Richard Ritchie, who is sponsored by Lord Howard of Rising, and CARE head of public affairs Nola Leach, who is sponsored by the Bishop of Hereford, are among the notable public affairs people with passes.
Another is Telegraph Media Group head of public affairs Edward Taylor. He is sponsored by Lord Black of Brentwood, an executive director at the same organisation.
However, PRCA and APPC codes state that political consultants must not hold, or permit any staff member to hold, a pass entitling them to access the Palace of Westminster. It has also been suggested that holding a pass will be prohibited in the soon-to-be-refreshed CIPR code.
PRCA CEO Francis Ingham stated that the holding of parliamentary passes by public affairs practitioners was 'a highly contentious area'.
'In some cases, the need for a pass is clear and legitimate. In others though, it is hard to understand why somebody holds a pass other than the fact they are mates of a parliamentarian and prefer not to queue up with other members of the public.
'The simple rule should be that if you hold a pass, you must be doing work to justify it. In many cases, that appears simply not to be the case.'
APPC chairman Michael Burrell agreed that holding a pass was 'unnecessary and inappropriate' for PA practitioners, while Insight Public Affairs director James Tyrell said that it was 'astonishing' to see the number of lobbyists in possession of a pass.
He added: 'This week, Nick Clegg reiterated that the problem with lobbying was one of "public perception".
'This kind of activity does little to redress this and is why any future regulation must apply universally to consultancy lobbyists, in-house, freelancers, charities, management consultants, lawyers and anyone else engaged in public affairs activity.'