Japan’s defence ministry has requested its biggest ever budget to bolster its ability to protect outlying islands in response to China’s growing military reach in the region.

The ministry has asked for 5.09 trillion yen (£27bn) for the financial year starting in April 2016, amid concern over Beijing’s construction of artificial bases in the South China Sea and its claims to the disputed Senkaku/Diaoyu island chain in the East China Sea

If approved, the defence budget would be Japan’s biggest ever, after the fourth increase in as many years. The budget will be drafted into a bill in December and submitted to parliament for approval.

Japan had been making annual cuts to its defence budget for a decade up to 2013. The increases since then reflect its growing anxiety about China’s expanding naval reach. The rise is also in line with Japan’s more assertive defence policy under the conservative prime minister, Shinzo Abe, as he seeks to check Chinese influence and expand the scope of his country’s military.

Abe’s ongoing attempts to push through legislation that would allow Japanese troops to fight alongside allies on foreign soil for the first time since the end of the second world war brought tens of thousands of people out in protest on Sunday [1].

Monday’s budget request, an increase of 2.2% on last year, demonstrates a shift in Japan’s security emphasis from its northern maritime border with Russia to its long and porous southern reaches. In contrast to previous investment in tanks and heavy artillery, it is building a more flexible and mobile force – including its own version of the US marine corps – that would be able to quickly defend territory against an invading enemy.

Japan’s defence budget is still dwarfed by that of China, where military spending rose by more than 10% this year to £90bn.

China is second only to the US, which spent $581bn (£377bn) on defence in 2014, while Japan was ranked seventh, according to the International Institute of Strategic Studies in London.

In 2010 China accounted for about 28% of defence spending in Asia, but by 2014 its share had increased to 38%, according to IISS. Japan’s share of regional military spending, meanwhile, fell from 20% in 2010 to just below 14% last year.

Much of the hardware included in Japan’s new budget is designed to monitor outlying territories and repel any attempt to invade the Senkaku islands, which are administered by Japan but claimed by China.

Japan is building a military radar station on Yonaguni island, just 94 miles south of the islands.

According to a request submitted on Monday, the ministry’s shopping list includes amphibious assault vehicles, stealth warplanes, F-35 Osprey tilt-rotor aircraft, F-35 fighters and an advanced Aegis radar-equipped destroyer.

It also wants to acquire Global Hawk drones and surveillance helicopters to defend far-flung islands along an 870-mile stretch of ocean between the Japanese mainland and waters off Taiwan.

The ministry is also seeking extra cash to build new military bases and expand existing ones on some of the islands, equipping them with state-of-the-art radar and missile batteries.

Ministry officials have set aside £58m to expand an army base on Miyakojima island, 188 miles east of Yonaguni, and £47m to build a base on Amami Oshima, an island midway between the main Okinawan island and the Japanese mainland.

Chinese surveillance vessels briefly sailed into Japanese territorial waters around the Senkaku islands last week, the 23^rd time they have done so this year, the Japan coastguard said.

“Beijing hasn’t stopped sending its official vessels either into the contiguous or the territorial waters of the Senkakus,” a Japanese government official told the Guardian.

The official added that Beijing had also broken international agreements to conduct only joint exploration of gas and oil fields in disputed areas of the East China Sea.

“Against that background, the Beijing-Tokyo relationship cannot improve in any substantial way,” he said. “Yet it is still very important for the two countries to have a manageable relationship.”

Justin McCurry in Tokyo