A group of Philippine MPs said Monday they would visit the Spratly islands this week to help assert their country's claim over the area amid tensions with rival claimant China.

The five lawmakers, most of them allies of Philippine President Benigno Aquino, said they would make the flight to the remote archipelago in the South China Sea on Wednesday to show Filipinos were willing to stand up to China.

"It really looks like China is acting like the enforcer, the bully of the Asia-Pacific region," one of the politicians, Teddy Brawner Baguilat, a member of Aquino's Liberal Party, told reporters.

The five will fly on a private chartered plane to Thitu island, the largest of the Philippine-occupied islands in the Spratlys, and spend about five hours there, the legislators told reporters.

About 60 Filipinos live on Thitu, which is just 37 hectares (91 acres) in size and about 450 kilometres (280 miles) northwest of Palawan island, the nearest major Philippine landmass.

China's closest big landmass is Hainan island, more than 900 kilometres away.

The group also plan to fly over other nearby disputed islets and reefs claimed by the Philippines where Chinese forces have allegedly taken aggressive actions recently to stake their country's territorial claims.

"It is a mission to firmly support the Philippine government's claim of sovereignty over the Kalayaan Islands," said Walden Bello, another of the legislators, using the term for the Philippine-claimed islands in the Spratlys.

Two of the five congressmen intending to make the trip are members of Aquino's Liberal Party, while two others are members of a smaller party that is part of the president's broader parliamentary coalition.

However Bello emphasised the trip was a private one and did not have Aquino's endorsement.

Spokespeople for Aquino's office could not be reached on Monday, while a spokesman for the foreign affairs department refused to comment.

China and the Philippines, along with Vietnam, Brunei, Malaysia and Taiwan, have overlapping claims to the Spratly islands and parts of the surrounding South China Sea, which are believed to sit on vast natural resources.

The Philippines has accused China in recent months of taking increasingly aggressive actions to stake their claims, such as opening fire on Filipino fishermen.

A 14-member delegation from a university in Taiwan completed a seven-day visit organised by the island's navy to Taiwanese-controlled Taiping, the biggest island in the Spratlys, on Monday the defence ministry said in a statement.