Shadow chancellor Oliver Letwin blamed the rate rise on the Government's inflation-busting increases in public spending. "For people with floating rate mortgages, this means that their interest payments will have risen by more than a third in the last nine months," he said. Mr Letwin added: "This is how people are paying today for Gordon Brown's fat government, big spending and big borrowing as the Bank of England tries to cool down the economy he is overheating.