Irresponsible bankers who take unacceptable risks or mis-sell products to customers should be barred from the profession, Ed Miliband has said.
The Labour leader demanded tough new rules allowing regulators to "strike off" reckless City staff in the same way negligent midwives and doctors can be ruled unfit for practice.
He said: "Banking should be a trusted profession. Other professions - such as medicine and the law - have codes of conduct and disciplinary rules.
"Bankers should be held to account to ensure they act with integrity, in the best interests of their customers, and in the best interests of the wider public."
Mr Miliband's call came ahead of Monday's publication of the Independent Commission on Banking's (ICB) final report which will make recommendations on how to prevent another banking crisis.
The Government launched the ICB, chaired by Sir John Vickers, last year to find ways of avoiding another banking crisis and taxpayer bailout.
Mr Miliband said: "It is crucial we learn the right lessons from the financial crisis as we seek to ensure it does not happen again and build a different kind of economy that will meet the big challenges of the future. We should never have to bail the banks out again. To guarantee that we need the serious and lasting reform."
Meanwhile, Business Secretary Vince Cable warned the industry to prepare for sweeping reforms so they could never again use "the deposits of British savers to play the banking equivalent of the roulette wheel".
Writing in The Mail on Sunday, he criticised institutions which continue to award top staff "lavish remuneration packages". Mr Cable said: "Banks must be left under no illusions that reform is coming. The recession is not an excuse for postponing banking reform. Indeed our economic recovery depends on it."
Chief Secretary to the Treasury Danny Alexander later dismissed reports Mr Cable would quit if the Government delayed implementing Sir John's recommendations. He told Sky News he had spoken to the Business Secretary and the claims were "total nonsense", adding: "The important thing here is to get on with the job of sorting out our banking system."