Moves to fast track US approval processes for the planned Trans-Pacific Partnership free trade deal have narrowly passed the House of Representatives but need fresh Senate approval.

US president Barack Obama is asking Congress to pass a "fast track" bill that will mean a final agreement can only be approved or rejected by Congress once a deal is struck, and not amended.

Other countries negotiating the TPP want a fast track to be approved in the US as a condition for further negotiations to finalise the deal.

The House of Representatives last night passed the fast track bill by 218 votes to 208, but dropped some provisions designed to assist workers who lose their jobs as a result of trade deals.

Australian fair trade campaigner Dr Patricia Ranald from AFTINET said those changes make it less likely the bill will receive the required level of support in the Senate.

"The Senate process requires a 60-vote majority out of 100 [senators] for a procedural vote to enable the new fast track bill to be debated by the Senate next week. This is less likely without the accompanying workers' support legislation," said Dr Ranald in a statement.

"Since other TPP governments have refused to finalise the negotiations without fast track, this means TPP negotiations between Australia the US, Japan and nine other countries are still on hold, and the TPP trade ministers' meeting tentatively set for late June has been postponed yet again."

Spokesmen for Mr Obama have said that both the fast track and workers' support measures must reach the presidents desk for approval in order for the fast track to proceed.