The measure is aimed at preventing banks from making risky trades for profit, but as regulators work to implement the rule, they have come under heavy fire from the business and financial communities, as well as Republicans, who contend strict rules could stifle American markets.
A quintet of regulators — the Comptroller of the Currency, Commodity Futures Trading Commission, Federal Deposit Insurance Corporation, Federal Reserve, and Securities and Exchange Commission — have been given the joint mission of making the rule a reality.
Those watchdogs have been poring over thousands of public comments on their October proposed rule, which ran hundreds of pages and asked a litany of questions seeking further input.
Levin and Merkley were among those weighing in via comment letters, calling the original proposal for being too complex and too accommodating to financial interests. But they maintained their desire to see a workable rule in place before the fall season.
"To be sure, the proposed rule is not perfect, but it should not be delayed or scrapped," they wrote in Thursday's letter.
Rep. Barney Frank (D-Mass.) has similarly criticized lawmakers for making the rules too complicated, and previously called on regulators to finish a simplified version of the rule by Labor Day.
Given the workload they face, and the number of competing interests seeking to sway the rule, regulators have said they do not expect to meet the July 21 statutory deadline for finalizing the rule.
Earlier this month, regulators issued a joint statement making clear that financial institutions would have two years from that deadline to fully comply with the rule, and that the window could be extended if the Fed deems it necessary.