By David Brunnstrom
WASHINGTON (Reuters) - Britain said on Monday a ruling expected in the next few months in an international arbitration case the Philippines has brought against China's South China Sea claims must be binding.
Hugo Swire, British minister of state responsible for East Asia, also said Britain saw the ruling from the Permanent Court of Arbitration in The Hague as an opportunity for China and the Philippines to renewed dialogue over their territorial disputes.
China claims virtually all of the South China Sea and rejects the court's authority in the case, which is widely expected to go in favor of the Philippines, significantly raising tensions in the strategic waterway.
The court is expected to rule in late May or early June.
Swire said that although Britain's relations with China had warmed and it was keen to attract Chinese investment, this did not mean "we suspend our critical faculties" over Beijing's human rights abuses or its assertive pursuit of territory in the South China Sea.
"We make it clear to the Chinese that we can only do these kinds of deals in an open and transparent way under an international rules-based system," he told Washington's Center for Strategic and International Studies think tank.
"Under the international rules-based system on which the world depends, we would expect the ruling from The Hague to be adhered to by all parties concerned, whichever way it goes and we would stand by others, including the United States, whichever way that ruling goes."
In February, the United States and the European Union, of which Britain is a part, warned China it should respect the ruling from The Hague. The court has no powers of enforcement and its rulings have been ignored before.
Washington has expressed concerns that China may use a negative ruling as a pretext to declare an air defense identification zone (ADIZ) in the South China Sea, which would require notification when passing through the airspace of one of the world's busiest trade routes.
Swire said Britain considered freedom of navigation and overflight "absolutely non-negotiable."
Britain has prioritized developing economic ties with China and welcomed Chinese President Xi Jinping on a state visit in October, leading critics to accuse it of placing short-term financial gain above human rights and security interests.
It also upset the U.S. administration when it became the first non-Asian country and the first member of the Group of Seven advanced economies to join a China-backed development bank for Asia seen by Washington was an unwelcome rival to Western-led institutions, such as the World Bank.
(Reporting by David Brunnstrom, editing by G Crosse)