I have not found the actual directive to check it out myself but I find it hard to believe that cash is a no-no. I thought that bank notes were legal tender for all debts.
Most people will not be affected by this but it will badly hit poor people who don't have bank accounts and who may not be eligible to get them for one reason or another.
Does that mean that John Smith of Park Bench No. 5, People's Park, Grimsby will have to get a postal order at considerable expense to pay for his Vanquis credit card bill?