The Department of Labor fiduciary rule should not face any further delays, the Financial Planning Coalition told Congress in a letter sent Tuesday.

The coalition's members—the Certified Financial Planner Board of Standards, the Financial Planning Association and the National Association of Personal Financial Advisors—asked members of the Senate and House to oppose any action that would delay or prevent implementation of the DOL rule.

Opponents of the rule, implementation of which already has been delayed from April until June, are aggressively advocating that the DOL be permanently prohibited from implementing the measure, the coalition says.

“This advocacy is based on the mistaken belief that an alternative to the fiduciary rule is needed,” the group says in the letter. “We urge you to strongly oppose any rider [on pending legislation] that will delay or prevent implementation of the fiduciary rule, which requires financial professionals to provide retirement investment advice in the best interest of retirement investors.”

“Any congressional action would effectively kill the fiduciary rule, leaving American retirement savers unprotected from investment advice that is not in their best interest. Congressional action is unnecessary given the extraordinarily lengthy and transparent notice and comment process that has already occurred,” the coalition added.