I think it's fair to say that in light of the latest expenses scandal surrounding the Home Secretary, along with the ongoing issues around "Lords for Hire", the real problem that politicians face these days is as much about perception as it is about actual action. If you can be perceived to be conflicted in some way, that can, after all, be just as damaging as actually being guilty of acting in an inappropriate and unparliamentary way.
Take for example, David Lammy MP, the Minister of State for Higher Education and Intellectual Property. Part of his work remit involves responsibility for "developing and implementing through the Intellectual Property Office an intellectual property system that promotes creativity and innovation in the UK". At the same time, Lammy also registers with the Commons authorities that he receives financial "support towards the cost of employing a social policy research assistant" from Lord Alli and Lord Hollick.
Now, according to Register of Lords Interests, Lord Alli, amongst many other renumerated directorships, is a paid Director of Chorian Ltd, which "through its subsidiaries, engages in the ownership, development, and management of intellectual property brands." Meanwhile, the Register notes that Lord Hollick is a Director of Honeywell International Inc which amongst the many things it does has an international intellectual property arm.
Now, I'm not making any suggestion that any rules have been broken by either David Lammy, Lord Ali or Lord Hollicks, but in these matters, as I said above, perception can often be just as important as reality for the contemporary politician. It's a bit of tightrope to be sure.