Quote: But the Prime Minister told MPs that "the difference between having a retail and an investment bank is not the cause" of the sector's problems.
"He has got to remember that Northern Rock was effectively a retail bank and it collapsed. Lehman Brothers was effectively an investment bank without a retail bank and it collapsed," he said.
"So the difference between having a retail and an investment bank is not the cause of the problem.
"The cause of the problem is that banks have been insufficiently regulated at a global level and we have got to set the standards for that for the future."
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