Legislation to outlaw old-style bank bonuses and punish banks who continue to pay them will be produced within weeks, Gordon Brown has said.
"Enough is enough. I am not going to stand by and allow people to return to...the bad old days," the Prime Minister told BBC1's Andrew Marr Show.
"Just as we will have a Fiscal Responsibility Act to deal with public finances, we will come back and we will have a new Business and Financial Services Act as well that will ban the old bonus systems and make it impossible for firms to go back to using them.
"It will also say that where there is bad behaviour, the Financial Services Authority will have the right to intervene and where companies are not prepared to act in a way which is consistent with all the new proposals about the fair treatment of bonuses and remuneration there will be penalties imposed on these companies."
The measure will be included in the forthcoming Queen's Speech.
Fellow leaders at the G20 summit in the US this week had all been convinced that the banks were "anxious to return to the bad old days", he said.