The European Parliament on Wednesday approved an accord with Japan that has been dubbed the world's biggest trade deal, covering economies that represent a third of the world's GDP.

The agreement will go into effect in February and was celebrated as a victory for Europe as a free trade champion in the face of U.S. President Donald Trump's protectionism and Britain's decision to leave the European Union (EU).

"Our economic partnership with Japan – the biggest trade zone ever negotiated – is now very close to becoming a reality," EU Trade Commissioner Cecilia Malmstrom said.

But, ironically, some EU leaders see the wide-ranging deal they have agreed with far-off Japan as a possible model for future commercial relations with the UK, once it formally quits the bloc.

"Everything is uncertain with the United Kingdom for the moment, but one day or another we'll have to negotiate something," Malmstrom said, predicting a British deal would "go even further" than Japan's.

Covering more than 630 million people and economies that add up to around a third of the global output, the EU-Japan Economic Partnership Agreement has been under discussion since 2013.

When it goes into effect it will regulate almost all commerce between Japan and the 27 remaining EU economies and, according to Malmstrom, will benefit in particular European farmers.

Once the deal is fully implemented, some 85 percent of EU farm products will be eligible for tariff-free export to Japan, although in some cases this will come after a period of transition.

Customs duties on beef, for example, will be progressively reduced, and rice, a source of national pride in Japan, will be excluded from the deal.

Tokyo has also agreed to recognize more than 200 "geographic signifiers", allowing iconic European products like Roquefort cheese, Tyrolean speck and Polish Vodka to protect their brand value.

For their part, the Japanese will win free access to the European automobile market after a multi-year transition period.