There is the Competition Act 1998 to bear in mind as well:
"The Competition Act 1998 came into force on the 1 March 2000. It introduces two main prohibitions:
Chapter I: a prohibition of anti-competitive agreements, based closely on Article 81 of the EC treaty; and
Chapter II: a prohibition of abuse of a dominant position in a market, based closely on Article 82 of the EC Treaty
Key aspects of the new legislation are:
anti-competitive agreements, cartels and abuses of a dominant position are now unlawful from the outset;
businesses which infringe the prohibitions are liable to financial penalties of up to 10% of UK turnover for up to 3 years ;
competitors and customers are entitled to seek damages;
the Director General of Fair Trading has new powers to step in at the outset to stop anti-competitive behaviour;
investigators are able to launch 'dawn raids', and to enter premises with reasonable force; and
the new leniency policy will make it easier for cartels to be exposed
The intention is to create a regulatory framework that is tough on those who seek to impair competition but allows those who do compete fairly the opportunity to thrive."
from:
http://www.dti.gov.uk/ccp/topics2/competition_act.htm
If a company has practices which prevent a level playing field - they are breaking the law.
In this case, it would seem to me to have been more reasonable for the Trust to have contacted you and asked for your credentials, and offered to put you on their list, so that you could do the work (should you pass the normal requirements).
These lists may well be illegal in any case, just no-one has questioned/noticed/wants to rock the boat.
