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Similarly, Randy G. DeFrehn, executive director of the National Coordinating Committee for Multiemployer Plans, said in the amendment "gives multiemployer pension plans the tools they need to head off insolvency and preserve retiree benefits for decades to come." 

Also, the options in the amendment means there will not be "a massive taxpayer bailout and instead provides a path forward for these troubled pension plans that preserves benefits at higher levels than allowed under previous law. This landmark action also keeps employers in the system and in business, preserving jobs and ensuring economic growth," he said.

Supporters point out that the amendment provides for workers and retirees to vote on whether they want to cut their own benefits. It is also seen as a way to help the Pension Benefit Guaranty Corp. remain solvent. And it has provisions which eliminate the penalty on employers who increase their contributions to underfunded plans.

On the other hand, Karen Friedman, executive vice president of the Pension Rights Center, said it was a "travesty" that on the 40th anniversary of the enactment of the Employee Retirement Income Security Act the House "has swept away a fundamental and sacred principle of the law: that once a retiree has begun receiving a pension, it cannot be reduced unless a plan runs completely out of money." 

She pointed out that financially-troubled multiemployer pension plans will be able to cut retiree benefits by up to 60 percent if plan assets face depletion in 10 to 20 years.

"Also extremely troubling is the secretive process by which these provisions were pushed through Congress, buried in a must-pass bill in the last days of a lame-duck session, without input from the pensioners whose lives could be devastated by the cutbacks authorized by the measure," she added. "The process was undemocratic and unfair."

The Senate has until midnight Saturday to pass the spending bill in order to avoid a shutdown of the federal government.

Among those senators opposing the amendment was Sen. Ron Wyden, an Oregon Democrat.

"We've seen this movie before and it never ends well – a last-minute scheme worked out largely in private to solve a complex problem without the full and public consideration of Congress," Wyden said in a statement. "The last-minute scheme was rushed through by a few House members in private during the final days of the legislative year without consideration by the Senate Finance Committee and other committees of jurisdiction."

He called it a "flawed process" that resulted in a "lopsided solution" which leads to "existing retirees to shoulder a disproportionate share of sacrifice. It also will result in the rolling back of a major tenet enshrined in pension law – never take away money a pensioner has already earned," he added.

There currently are more than 1,400 multiemployer plans covering about 10 million people.

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