Caz, many people accept that there is a need for some sort of change but feel that could be achieved more fairly - and cheaply - by tweaking the current system rather than implementing this new one. For instance, simply reviewing the people who have not seen in the past few years (eg those given lifelong awards in the past) could help. However, continually retesting people with chronic, or even degenerative, conditions is a waste of time and momeny.
Irrespective of whether there is a duty to consult, once the consultation process has started there are certain rules which should be kept - the government actually broke several of these rules and then pressed ahead with change before the end of the consultation period. It seems clear that the wish to cut the bill by 20% (bearing in mind that government figures estimate at 0.5% fraud rate) was the driving force behind this idea which was going to be pushed through, no matter what anyone else thought.