Does asking the bank for patience/discounts on interest fees with my bank affect my credit rating?

I am almost at my credit limit, and currently unemployed. It seems prudent to speak with my bank and ask for some leeway given my circumstances, it would not be strictly necessary so I wouldn't wish to sacrifice my good credit rating for something that's only going to save me 15 pounds or so per month. I believe that the banks can get tax savings from Revenue and Customs if you inform them in advance of difficulties.