According to the BBC article, the Prime Minister's position is thus:
The prime minister denied the government was stigmatising people who were genuinely ill but said the public believed recipients should be "people who are incapacitated through no fault of their own".
No fault of their own, what a strange concept. Does the man intend to start assessing not only the practical limitations of a person's condition, but also the degree of fault involved?
"But there are some who are on these benefits who do not deserve them and frankly we are not doing our job looking after taxpayers' money if we do not try and make sure these people go to work."
Benefits are not given based on being deserving. They are given based on need. Going to work or not isn't based on being deserving. It's based on ability. An idiot who drove while high/drunk/ill/tired and smashed up his car and his head so badly that neither will ever function again is probably not considered very "deserving", but his needs will be pretty high and he's unlikely to work again. A young fireman who lost a leg while saving a helpless baby from a burning building is about as deserving as they come, but his needs, while substantial, will be easier to adapt for, and with a relatively small amount of equipment and support the chances are he will be able to do some work.
I wonder... if someone were declared Fit For Work despite a serious health condition, and in the course of making the effort to keep up with the Mandatory Work Related Activity requirement of JSA, their condition permanently worsened to the point where even the DWP and ATOS accept that they are too ill to work - would it be their fault for not saying "I can't do this," and risking having their JSA stopped?
Even taking the sort of example that I think the government mean, it's worrying. Let's imagine, for a moment, that we have a claimant, an alcoholic, and that his alcohol dependency didn't evolve as self-medication for a pre-existing but untreated mental health condition. Let's accept the government assumption that he really did skip gleefully out of the careers office at school saying "I've got a better idea, I'll get pished and the taxpayer will take care of me, bwahahahahaha!" Fixed this in your head? Good.
Now we're twenty years down the line, he has no friends and family left apart from other alcoholics, no work history, very few self-care skills, and all the physical and mental effects of long term alcohol abuse, which if you're not too squeamish you can look up for yourself. There are very few jobs that such a person could do, and even fewer employers who would take such a person on. Then what happens?
Cameron's despicable lie is that his ideal outcome involves people with dependency issues being treated and then helped to find jobs. That will never happen. It is far too expensive, and without wishing to sound defeatist, in many cases it's an impossible outcome.
We could put him into a treatment programme - one that isn't dependent on turning up sober (unlikely), and that won't send him back to his bedsit and alcoholic pals to undo all the work that has been done (so we're looking at an open-ended residential placement - unlikely, and extremely expensive). Then once he's sober, he'll be allowed to access NHS treatment for the underlying mental health conditions that will have developed (unlikely and expensive) and the physical damage as well (amazingly expensive). We'll have to hope that during those years - yes, years - the DWP don't choose him as an easy target and put him under so much pressure that he cracks and starts drinking again. Eventually, after many years of intensive treatment, a lot of money, even more hard work, and a dollop of luck on the side, he might be able to re-enter some sort of employment for a few years until he (a) retires, (b) dies of the irreversible physical damage, or (c) falls off the wagon again.
Cynically speaking, and please don't think I'm advocating this, it is in fact cheaper to allow him to quietly drink himself into an early grave without intervention.
Cameron might talk up "treatment" and "employment" but until we see actions to that effect - boosting rather than cutting the support projects* - what he really means by "getting people off disability benefits," is saving money by consigning them to the lower unemployment benefits.
The benefits system is supposed to be the last safety net. It does not provide a luxury lifestyle, it doesn't try to improve matters, it merely attempts to go towards providing what has been defined as the minimum amount of support necessary for that person to live in conditions that can be considered acceptable for a human being. Reducing that support does not propel people into sustainable jobs, it just makes their lives more difficult and in many cases perpetuates their problems, or in a few very sad cases, hastens their deaths.
*Yes, the article speaks of a £580m investment. However, this is from "private and voluntary organisations", eg not the government, and frankly it's a drop in the ocean compared to the cost of effective long-term treatment and support for that many addicts.