My colleague Gerry has written a blog about tax avoidance v's tax evasion.

http://www.critchleys.co.uk/blog/2014/05/21/take-that,-tax-avoidance/

We at Critchleys are very pleased that we did not succumb to selling aggressive tax schemes, despite being targeted by the companies who put them in place (and yes, it is usually a third party scheme rather than one cooked up by a clever accountant/ tax adviser).