China publishes new details of its sweeping claims to South China Sea in row over Philippine law

China has published new details of its claims to a contested shoal in the South China Sea in the latest clash over maritime territory with the Philippines.

Officials from the Chinese foreign ministry shared new coordinates for what it considers to be the country’s baseline, a term used in defining a country’s territorial waters that normally matches its coastline.

Beijing set its baseline around the Scarborough shoal, however, claiming that the contested atoll should be the starting point for considering much of the entire South China Sea as Chinese territorial waters or its exclusive economic zone.

A statement by the Chinese foreign ministry said delimiting the Scarborough shoal was a “natural step by the Chinese government to lawfully strengthen marine management and is consistent with international law and common practices”.

The move from Beijing came a day after the Philippines signed two laws defining the country’s maritime zones and right to resources, including in the South China Sea, with codifying claims that overlap significantly with China’s.

Philippine president Ferdinand Marcos Jr signed the two laws – the Philippine Maritime Zones Act and the Philippine Archipelagic Sea Lanes Act – in a nationally televised ceremony attended by top military and national security officials. The new law stipulates jail terms and stiff fines for violators of these zones.

Beijing said in its statement on Sunday that the first of the two laws signed by Marcos violates China’s “sovereignty” over most of the South China Sea.

“China firmly opposes it and will continue to do everything necessary in accordance with law to firmly defend its territorial sovereignty and maritime rights and interests,” the foreign ministry said.

China disputes control of the South China Sea, which includes some of the world’s busiest shipping routes, with several Southeast Asian nations including the Philippines and Vietnam.

On Friday, the Chinese foreign ministry summoned the Philippines ambassador to China to mark their “stern protest” to the proposed laws, which it called an attempt to “solidify the illegal ruling of the South China Sea arbitration case through domestic legislation”.

That statement refers to a 2016 ruling by an international court of arbitration, which found that most of China’s claims in the South China Sea were invalid. Beijing has rejected the ruling.

"We strongly condemn and firmly oppose this situation. China’s territorial sovereignty and maritime rights in the South China Sea are firmly based on historical and legal grounds,” Chinese foreign affairs ministry spokesperson Mao Ning said.

Both China and the Philippines claim Scarborough shoal and other outcrops in the South China Sea. China seized the shoal, which lies west of the main Philippine island of Luzon, in 2012 and has since restricted access to Filipino fishermen.

Tensions between the Chinese and Philippine coastguards and naval forces have surged at an alarming rate since last year, sparking fears that the US and other regional powers may get drawn into a major conflict over the disputed waters in the South China Sea.