Speaking before a federal inquiry, Mr Abbott said there should be no barriers to the UK joining the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, or CPTPP, despite it not being in the Pacific region.

"It's a no-brainer bringing Britain into the CPTPP, and I hope it will be as soon as possible," he said.

"The admission of the UK would send a strong signal that the CPTPP is an outward-looking entity that wishes to welcome into its ranks all countries that wish to trade freely."

The former prime minister serves as an adviser to the UK's Board of Trade, despite controversy over his appointment to the role.

Mr Abbott said the admission of the UK could be a way to welcome the US back into the fold for the partnership, after former president Donald Trump withdrew American support for the agreement's predecessor, the Trans-Pacific Partnership.

"One of our great regrets is the US, in the end, did not join the TPP," Mr Abbott said.

"I hope the accession of the UK will be a catalyst for the US to reconsider its non-membership."

The CPTPP was signed by 11 nations - including Australia, Canada, New Zealand and Japan - in 2018.

Membership to the agreement requires the unanimous support of the member nations.

China earlier this month formally applied to join the partnership.

Mr Abbott highlighted concerns with China's potential entry.

"In no way should China be allowed anywhere near the TPP until, at the very least, it drops its trade boycott of Australia," he said.

"The last thing we need is further integration of China into the world economic order."

Australian Associated Press