Vermont Sen. Bernie Sanders called on Democratic presidential rival Hillary Rodham Clinton on Thursday to say exactly where she stands on President Barack Obama's trade agenda now that Congress is considering it.

"I think our trade policies have been disastrous," Sanders said during a breakfast sponsored by The Christian Science Monitor. "Secretary Clinton, if she's against this, we need her to speak out right now. Right now. And I don't understand how any candidate, Democrat or Republican, is not speaking out on this issue right now."

The House was starting debate on so-called fast-track authority, which would let the administration complete a trade deal with Pacific countries that Congress could accept or reject, but not change. The proposed Trans-Pacific Partnership would lower trade barriers among 12 nations.

Clinton, a former secretary of state, has expressed concern that the deal may allow currency manipulation and fall short on health and environmental protections. But she's said she wants to see the agreement in its final form before judging it. Sanders and former Maryland Gov. Martin O'Malley, who is also seeking the Democratic presidential nomination, vigorously oppose the deal.

Clinton aides did not immediately comment on Sanders' remarks. Clinton has been under pressure to oppose Obama's plan from labor unions and liberal groups, which say it would ship jobs overseas and undermine health and environmental standards.

Republicans who lead Congress are planning votes Friday on a program to retrain workers displaced by trade agreements, called Trade Adjustment Assistance, and fast-track authority may be voted on then, too.

Sanders, who launched his presidential bid in late April, has drawn large crowds to his events in Iowa and New Hampshire and estimates he has raised $8 million for his presidential campaign, based on about 200,000 contributors donating an average of $40.

The Vermont independent, who sides with Democrats in the Senate, predicted he can raise $40 million to $50 million by the Iowa caucuses and New Hampshire primary in early 2016.

The self-described democratic socialist said his campaign manager had recently traveled to Iowa and was hiring staff in preparation for the caucuses. "We're gearing up," he said.

"This is not an educational campaign," Sanders said. "This is not a protest campaign. This is a campaign to win."

Sanders acknowledged Clinton is the "heavy favorite" at the start of the campaign but said "we have momentum. And our numbers are growing."