Hillary Clinton, the frontrunner for the Democratic presidential nomination, has opposed the Trans-Pacific Partnership, delivering a big blow to President Barack Obama’s efforts to sell the Pacific-Rim trade deal to Congress.

“As of today, I am not in favour of what I have learned about it,” Mrs Clinton told PBS television two days after the landmark trade pact was concluded. “I don’t believe it’s going to meet the high bar I have set.”

Her position marks a big setback for Mr Obama whose team has spent five years negotiating with Japan and 10 other Pacific Rim nations that account for 40 per cent of the world economy. Mr Obama wants to get TPP through Congress before he leaves office in January 2017, but Mrs Clinton’s move is an example of how presidential politics will complicate those efforts.