Petition Limitation of bank interest rates

There should be a correlation between the bank of England's base rate and the maximum amount of interest charged by financial institutions. My personal belief is that no institution or individual should be permitted to charge more than 6% above the bank of England's base rate. This should apply to loans, overdrafts, motgages and credit cards. Likewise, no institution or individual should be permitted to pay more than 3% less than their interest charges to savers with accounts requiring notice of withdrawal.
My reason for this law is to ensure that the consumer has more available money to help keep our economy vibrant rather than helping to increase the profits of the bankers.