As you are aware you are now committed to repaying debts 2,3 and 4 because you have made regular recent payments. The main question is what to do about debt 1 to Tesco that has not actively been pursued yet, but has already been issued a CCJ.?

This pursual could be re-instated at anytime as you know within Six years, after that they would have to return to the court, the fact a CCJ currently exists would make it difficult for the creditor to reapply and demonstrate to a court why they have not been pro-active in taking measure to try to contact you in regards to making more of an effort, this could count against them resulting in the court refusing to re-impose a new order.

On balance carry on the good work of paying 2,3 and 4 off totally clearing them and see what happens in the meantime, at least it gives you some breathing space whilst they leave you to fully clear what you are concentrating on at the moment. Be cautious though; out of the Blue Tesco could suddenly start purual of their debt at anytime within the Six year period, or apply for a AEO or a charging order to be placed on your property (if you own one).

If on the contrary Tesco don't take any action then sit back and "play it by ear", if it reaches Six years and they decide to pursue, then they would have to return to the court showing just cause why the CCJ should be re-applied...this could be difficult to say the least, if they have not made any effort or taken any form of recovery action in the first Six years...the refusal of a court to extend a CCJ through Tesco's inadequacies or carefree attitude would result in this debt becoming statute barred under those circumstances.