Firstly a DMP is only really worth doing if you really think your situation will improve within a year or 2 at the most, and you'll eventually be able to repay the debt in full, agree a settlement figure (less than that owed), or get the account back to an agreed monthly payment for the loan term. The last option will probably not be available if they have already terminated your original account/agreement and passed it to a
DCA
.
Secondly a DMP does not bind any creditor to anything. It's simply an "informal" agreement to make low monthly payments until your situation improves. This is the case whether you do it yourself, with the advice of and using the forms supplied by the cccs, or by letting the cccs do it all for you. The creditors have no obligation to accept the lower payment amount and could take action against you at any time.
However (and it is a big "However"). The fact is, if you agree to pay something towards the debt each month (even if it is just £1), you accept that the debt is yours and that you are taking the matter seriously, you always reply to them when they contact you (this can be by post only, you don't need to give out your phone number), and you always make some sort of payment every month without fail, they will "almost never" take any legal action against you. This is the advice I was given by the cccs on several different occasions and my own experience - I never had any legal action against me in 4 years of struggling and making token payments.
Although they "can" take action against you they never really want to. It's a pain for them to deal with, time consuming, and expensive if they get nowhere anyway. Also if you've completed a financial budget plan, made a repayment proposal, and it all looks both realistic and fair, then there is no advantage for them in taking any action.
As far as a creditor petitioning for your bankruptcy, this rarely happens. It's just too expensive for them and they rarely get a decent amount of money for their time, money and effort.
I had a cccs DMP I managed myself for nearly 3 years (should have given up after a year

) and in most cases (even where the loan balance was nearly £20k) they accepted £1 per month for all that time, no questions asked. In my experience, if you have a cccs number and send them the relevant forms they "usually" agree to very small payments. Not always though and people like Moorcroft can get quite nasty. It's just scare tactics though to get you to pay more than you can really afford. My advice is stick to your guns and don't leave yourself short. They're unlikely to take any action or send someone to your door if you are paying them something each month.
I hope this helps but please bear in mind that this is all just my experience, my opinions, and advice I've received from the cccs. What worked for me may not work for you (but it should really).