Japan has raised concerns about British proposals to invite Australia, India and South Korea to a meeting of Group of Seven foreign ministers and have them sign up to a joint charter with the forum, according to a diplomatic cable seen by Bloomberg.

Prime Minister Yoshihide Suga’s government "pushed back strongly,” the note says, arguing that the aim of the summit should be to rebuild the G7 after a difficult year, and not "institutionalize” a relationship with the invited guests.

The forum’s European members — France, Italy and Germany — hold similar views, and some of its diplomats have expressed concerns that the U.K. is attempting to reshape the G7 by the back door, by establishing a coalition of 10 leading democracies to counter China and other authoritarian states.