Britain has an agreement at the World Trade Organization (WTO) to remain within the WTO's Government Procurement Agreement after it exits the European Union (EU), Britain's mission said.

Britain is a member of the GPA, whose members open up their combined $1.7-trillion government procurement markets to each other's firms, by virtue of its EU membership.

There are 47 GPA members, including all EU countries. Australia is joining the block and China wants to become a member.

Diplomats agreed Britain's continuing membership post-Brexit in principle in November, saying few changes would be needed.

"Today’s decision underlines our determination to minimize any disruption, however, we leave the European Union," British Ambassador Julian Braithwaite said.

He added the EU, Montenegro, and Switzerland had had to amend their own membership terms to ensure continuity.

Membership would "ensure that British taxpayers and public sector organizationі, including government departments, continue to benefit from increased choice and value for money on contracts which are open to international competition. The agreement will continue to protect vital public services such as the NHS (National Health Service)," the British mission's statement noted.