[WASHINGTON] A top US trade union federation said on Wednesday it would withhold key election spending as it builds a war chest to fight President Barack Obama's pending trade deal with Asia.
The AFL-CIO said it was holding back funding for so-called Political Action Committees, heaping pressure on the White House and Democrats who support the trade deal.
The federation spent over US$9 million in the 2012 election cycle, largely funding Democrats, according to the Centre for Responsive Politics.
In a statement the AFL-CIO said it made the move "in order to conserve resources for the historic legislative battle around fast track (trade promotion authority) and the debate over the Trans-Pacific Partnership."
Mr Obama is seeking so-called fast-track authority that would allow the White House to agree the deal and submit it in its entirety to Congress to ratify, without the power to make amendments.
The trade deal would bring together a dozen nations including Australia, the United States, Japan, Mexico and Vietnam.
Political Action Committees support or oppose candidates and often behave like a guerrilla wing of an official campaign, although legally required to be independent.
The White House did not comment directly on the AFL-CIO announcement, but said Mr Obama would only support a deal if it was in the "best interests of American businesses and American middle class families."
"We understand that there are some groups that have traditionally been aligned with the Democratic Party that are very skeptical of any sort of trade deal," said White House spokesman Josh Earnest.
"We're going to have to prevail upon people... (to) take a good close look at the agreement once it's been produced."