Bete Noir Competition on Low Interest Rates on Cash ISAs

What is the worst cash ISA? It is somewhat ironic that interest returns on cash ISAs are not only so low but often lower than the same account outside an ISA wrapper even after taking into account 20% tax relief on the miniscule interest earned. But what is the worst cash ISA? I thought it was the Barclays cash ISA which offers an interest return of 0.1% paid annually in arrears. The real stinger here was that you could not transfer from it to Barclays more attractive Golden ISA paying interest of around 2.5%. In other words an investor has to cash-in the existing ISA and then reinvest. But the worst deal seems to be an account with Alliance & Leicester (now owned by Santander) which for one client paid absolutely no interest in arrears in April. It is hard to beat that!