“As our economy continues to strengthen, it is critical that you do not further withhold the Volcker Rule protections from American families and businesses,” the senators wrote. “America is still feeling the effects of Wall Street’s bad bets. We can ill afford to let reform stall now.”

The Volcker Rule regulates banking and hedge fund trading to protect consumers from banks making risky investments and bets. Democrats cited the ending of the Volcker Rule under the Bush administration as part of the reason for the 2008 financial crisis.

“While American families and businesses should be enjoying the protection of the Volcker Rule, your agencies’ ongoing failure to implement these important protections has left them and our economy at greater risk of another financial crisis,” the letter stated. “In the years since the law was passed, we have all seen a series of high-profile trading losses at banks and non-bank financial companies — instances where the Volcker Rule, if properly implemented, could have prevented significant losses that once again have undermined confidence in our markets and institutions.”

Merkley and Levin were the lead authors of an eponymous provision of the Dodd-Frank Act otherwise known as the Volcker Rule. The law stipulated that the final rule was due on July 21, 2012.

“The U.S. Congress passed, and President Obama signed into law, the Merkley-Levin Provisions to ensure that banking institutions are in the business of taking deposits, making loans and serving customers, and not in the business of making high-risk proprietary bets,” Merkley and Levin wrote. “Until a strong Volcker Rule is firmly in place and meaningfully enforced, families, businesses and investors will continue to doubt the U.S. commitment to Wall Street reform, and U.S. taxpayers will remain exposed to the dangers of high-risk trading and conflicts of interest by Wall Street’s largest firms.”

The senators added that they want the rule implemented by the end of the year.

“The final regulations needed to implement the ban on high-risk trading and conflicts of interest should be issued without delay and no later than the end of the year, so that our financial institutions can speed the process of eliminating the risks and conflicts of interest that continue to endanger the U.S. financial system,” the letter stated.