@whynotmethen I feel your pain and there's a lot of bollocks and nastiness on this thread! Contrary to popular belief there are unscrupulous companies out there and people with CCJs that aren't necessarily their fault.
I received a CCJ and it massively affected my credit rating so if you can, definitely pay it within the month so that you can request it is removed from your credit file.
In my case, I had a significant overdraft in the days when banks would automatically increase your limit without you requesting it, but I had a good well paid job so it was no issue.
But then I was made redundant and could no longer afford to pay the £150 per month fees let alone pay off the £10k overdraft. Contacted my bank and asked if I could freeze the interest and charges and make an arrangement to repay it as a fixed affordable monthly amount, all fine.
18 months later my bank sold the debt to a debt collection agency who constantly hounded me to increase the monthly payments. I offered to double my payments and provided evidence of my incomings and outgoings and what I could afford, along with evidence that I was required to have no CCJs as part of my job and therefore taking me to court could affect my employment. But they didn't care. They wanted to quadruple the monthly payment and took me to court anyway.
I completed an income and expenditure form alongside my offer and was told to send it to the agency, which I did. They didn't submit it to the court with the paperwork and the court made judgement in their favour and awarded a monthly payment that was higher than my TOTAL INCOME because the court didn't have the necessary information. It was done through Northampton County Court (nowhere near where I live or where the company were based) which I later found out is a bulk processing court so debtors like to use it because it's a rubber stamping exercise usually in the debtors favour.
It cost me £300 to apply for a variation order to be heard at my local court, where I attended. Closed session with me, the judge and a legal representative from the agency. The judge was appalled with what they had done and openly berated their legal rep. The variation was found in favour and the award was changed to my original offer but the judge said that while what the debt collection agency had done was morally reprehensible, it was not illegal so as much as he would have liked to there was nothing he could do to overturn the CCJ.
My advice to you would be to pay the £300 to have the case heard at your local court and turn up in person, you'll find the judge fairer than at a bulk processing centre as they see you as a real person.