Chancellor George Osborne said he shared "some of this frustration and anger" that the public feel towards markets.
"If you go and shoplift at the local WH Smith, you go to prison, but the market trader on the trading floor of a big investment bank, and you rip off people to the tune of millions of pounds, there are no criminal offences available to deal with you," he said.
There was a lot of "totally understandable anger" over the last five years over the "biggest single economic crash of our lifetimes".
"The idea that just a couple of years on. you can go. 'Oh well, let's forget about all of that' and move on is a bit optimistic. It's going to take time and the financial services sector, and indeed in the regulators and the politicians responsible, have to prove to the public that things really have changed."
He added that people needed to see there were "tougher laws and tougher regulation, and people who commit crimes go to prison, that the banking system if it gets into trouble or individual banks that get into trouble will be bailed out by their creditors rather than by the taxpayers, and that there will be openness and transparency".