To be really clear, I (along with others) have a big-time objection to stratification and favoritism. But nonetheless, UKBA has gone ahead with its so-called 'Trusted Partners' scheme. These law firms and advisers were selected by UKBA on a number of criteria among which is their 'trustyworthyness'.
UKBA has nominated these firms to assist with sponsorship registration in the PBS, which doesn't affect you directly. But there's no question about it that individual applications submitted through a 'trusted partner' will fare better than others. Since that's the whole point, the collocation to *ALL* types of applications is inevitable.
The list is at...
http://www.ukba.homeoffice.gov.uk/employers/points/helpandsupport/additionalsupport/If you are considering using a law firm, you might want to make a hard copy because ILPA has asked UKBA to remove this page. And yesterday the Law Society sent UKBA a VERY STRONG letter of complaint also insisting that this page be removed.