Barney Frank, one of the architects of the Dodd-Frank Act, called Friday for both stringent standards and lenient enforcement around the financial reform law's much-watched Volcker Rule.

The provision, once finalized, "will be tougher than many of the people in this room would like to see, but I do not think it will interfere with the function of the economy," said Frank, the former chairman of the House Financial Services Committee, who retired from Congress last year.

Still, Frank said that regulators should go easy on banks learning how to comply with the provision's restrictions on proprietary trading and investment in hedge funds.

"When you get the Volcker Rule, there ought to be a very important enforcement principle: the first time an institution does something that their own regulator believes is in violation of the Volcker Rule, the response should be, 'Don't do that again.' No penalty," Frank said in a Q&A presentation with Politico's Ben White, during The Clearing House's annual conference.

"There are a lot of concepts in the law, very important concepts, where they state the principle and it gets meaning as it is regulated," Frank added.

Banks have spent three years trying to soften the impact of the Volcker Rule, which has already caused many companies to shut down once-lucrative proprietary trading operations. But the ongoing delays in the rule's implementation has frustrated the White House, regulators and even some bankers who are looking for certainty and clearly defined guidelines about what activities they will and will not be allowed to do once the rule is implemented.

"It has to get done," Bank of America (BAC) Chief Executive Brian Moynihan told American Banker on Thursday, after a panel discussion at the conference.

Moynihan declined to predict whether or not the Volcker Rule would be finalized by the White House's much-desired year-end deadline: "Ask them," he said, referring to the five regulatory agencies in charge of approving the rule.

Some officials from those agencies, including Securities and Exchange Commission Chairwoman Mary Jo White and Philadelphia Federal Reserve President Charles Plosser, have in recent days expressed skepticism about regulators' ability to release a final rule by the end of the year.

Maria Aspan is the national editor at American Banker.