I started writing a message a couple of days ago about why I thought Dr Myhill's campaign was seriously misjudged and likely to be a waste of time for everyone involved - but I'm experiencing a bout of brain fog at present, and I ended up with an overly long post which didn't seem to express my point particularly clearly. So I deleted it. I'll give it another try, and attempt to keep it shorter this time.
There is no way that we're going to get a public inquiry at present. No way. In the UK, public inquiries only get announced when there is existing widespread and ongoing concern (and anger) about an issue or episode. That issue needs to be stuck near the top of the news agenda, with successive media headlines screaming "This is a disgrace!" and "Something must be done!". It needs to be a major topic of disquiet in homes, workplaces and pubs, with the public clearly of the opinion that something untoward has happened and that there are questions that need answering. There needs to be no other easy steps that Government can take to soothe public concern and assure people that the situation is under control.
That's when you get a public inquiry - when there is widespread concern and the Government has no other way of making the issue go away. In order to assuage the public they say "We'll have a big, open independent enquiry into what has happened, blame will be apportioned and lessons will be learnt so this can't happen again" *. You don't get a public inquiry just because a handful of people - even a very large handful of people - go to their MP and ask for one. No widespread and vocal public concern about the treatment of ME = no chance of getting a public inquiry on the issue.
Public inquiries are ridiculously expensive (£5 million for Leveson part 1, over £13 million for Mid-Staffordshire, over £12 million for Chilcot) so the Government doesn't just hand them out like sweets whenever people ask for one. And when they *do* announce them, they try to control the terms of reference to stop them spiralling out of control and lasting years (like the Saville Inquiry into Bloody Sunday, which took 12 years and cost nearly £200 million - and that was supposedly focussed on the events that took place in a particular locale over a couple of hours...). So even if there was sufficient public demand for an inquiry into the treatment of ME, there's almost no chance of getting one that covers "decades of neglect" - the terms of reference would be much more limited.
Consequently this campaign - however well-meaning - is unfortunately a waste of time. If you want to go and talk to your MP about ME/CFS there are many more worthwhile things you could ask him/her to do than signal their support for a public inquiry.
(* - in reality what happens is that the Inquiry's report - full of conclusions and recommendations - is put on a shelf by the relevant Government department and ignored. Quite a few inquiry chairs have complained publicly that the Government failed to act on their report in the years that followed, and wondered what the point was of holding the Inquiry in the first place. The point - as I would have thought was obvious - is that the Government was seen to act, and the public concern was mollified. The Inquiry's conclusions and recommendations are an inconvenience that Government usually does its best to ignore. So even though there's no likelihood of a public inquiry on the treatment of ME, this is probably no great loss...)