Solomon Islanders will head to the polls this week, voting in an election that promises to bolster or blunt China's regional ambitions, with security consequences that will ripple far beyond the Pacific nation's palm-fringed shores.

Solomon Islands has veered into China's orbit under Prime Minister Manasseh Sogavare (R) (Andy Wong)

The archipelago, one of the world's least-developed countries, is the unlikely focal point of a diplomatic scramble pitting a rising China against Western rivals.

Solomon Islands has veered into China's orbit under Prime Minister Manasseh Sogavare, who inked a secret security pact with Beijing in 2022.

Sogavare has vowed to deepen these bonds if re-elected.

His challengers, meanwhile, are deeply sceptical of Beijing's influence in the archipelago, known as the Pacific's "Hapi Isles".

"Everyone knows this election is going to be very closely watched by the United States, by China, and by other Pacific island countries," said Solomon Islands expert Anouk Ride from Australian National University.

"It feels like the pressure is on."

- Lurch to China -

The former British colony gained independence in 1978, establishing diplomatic relations with Taiwan as one of its earliest foreign partners.

But those long-standing ties were abruptly junked in 2019, when a freshly installed Sogavare gave his full-throated backing to Beijing's "One China" stance.

A wave of Chinese aid and investment followed, including tens of millions of dollars for a state-of-the-art medical centre and a 10,000-seat athletics stadium.

In 2022, Solomon Islands signed a surprise security pact with Beijing, catching traditional partners Australia and the United States off guard.

Although the final details are murky, the Western allies fear the pact is the first step towards a permanent Chinese military base in the South Pacific -- something that could be a game-changer for security in the region.

China already maintains a small but conspicuous police presence in the nation, sending a revolving cadre of officers to train locals in shooting, riot tactics and martial arts.

Solomon Islands still bear the scars of the last time they were wedged between two chest-beating major powers.

Japan and the United States fought savagely over the Solomons at the height of World War II, littering it with unexploded bombs that still take lives today.

- Kidnappings and riots -

Elections are always boisterous, often tumultuous and sometimes violent in the nation of around 720,000 people.

In 2000, then-prime minister Bart Ulufa'alu was forced to resign after he was kidnapped by gunmen.

International peacekeepers were deployed to quell post-election violence in 2006, with premier Snyder Rini pushed out of office after just eight days.

In the lead-up to this year's vote, alcohol will be banned across the archipelago's 900 islands and coral atolls.

Sogavare's main rivals include Peter Kenilorea, a former United Nations lawyer who is akin to political royalty in Solomon Islands.

His father, Peter Kenilorea senior, was the nation's first prime minister after independence.

Matthew Wale, a chartered accountant and long-time human rights campaigner, is another prominent opposition figure.

Both Wale and Kenilorea have been sharply critical of the China security pact, signalling a possible change in direction if Sogavare loses.

- 'Master of mayhem' -

Sogavare has been Solomon Islands' dominant political figure of the past 20 years, holding the top office on four separate occasions since 2000.

A foreign academic once dubbed him the country's "master of mayhem", and critics fear his heavy-handed dealings look increasingly authoritarian.

In recent years, the 69-year-old karate black belt has tried to hose down dissent by threatening to ban meddlesome foreign journalists, Facebook and visiting diplomats.

Sogavare stared down widespread condemnation last year to delay the national elections by seven months.

"He has centralised power, and controls power, in a way that earlier prime ministers didn't," said historian Clive Moore, who has spent decades studying Solomon Islands.

But Sogavare's grip on power is far from absolute.

His embrace of Beijing in 2019 partly fuelled a wave of anti-government riots that tore through the Chinatown district in the capital Honiara.

Violence returned in 2021, when angry mobs tried to storm parliament, torched Chinatown and attempted to raze Sogavare's home.

While foreign diplomats sweat over the geopolitical consequences of the election, locals will be more consumed by creeping poverty and the paucity of jobs.

Solomon Islands ranks in the bottom quarter of the United Nations's human development index -- one spot above Haiti and several below war-torn Myanmar.

"There are other pressing issues right now," said Ride, who has lived and travelled throughout Solomon Islands.

"There is the health system, which has decayed to the point where you can't get basic medicines in your local clinic," she told AFP.

"Another one is the economy, and the impacts of the country going into further debt."

From toilet cleaner to 'master of mayhem': Solomon Islands PM Manasseh Sogavare

Solomon Islands Prime Minister Manasseh Sogavare has manoeuvered through armed coups, riots and the rise of China during four spasmodic spells as the Pacific nation's leader.

The 69-year-old has been a figure of international intrigue since regaining power in 2019, when he abruptly severed links with Taiwan and embraced overtures from China.

But those more familiar with politics in the Pacific know Sogavare was a magnet for controversy long before orchestrating this eye-catching switch.

Sogavare was born to missionary parents within the Seventh-day Adventist church, and his faith is a defining part of his public persona in the deeply Christian nation.

As is his rags-to-riches origin story: Sogavare claims he rose from a humble toilet cleaner in the country's public service to become the powerful Commissioner of Inland Revenue.

- Riots, coups and karate -

A spritely karate black belt with a penchant for angry outbursts in parliament, the teetotal taxman was first installed as premier in 2000 as ethnic violence swept the capital Honiara.

Armed rebels staged a coup by kidnapping then-prime minister Bart Ulufa'alu, promising to release him from their clutches only when he quit.

Sogavare took his place after cobbling together a thin coalition, but lasted little more than a year before he was voted out.

"He doesn't drink, he doesn't smoke and he keeps his body pretty healthy," said historian Clive Moore, who has studied the Solomon Islands over more than 30 years.

"You watch any film and you see Sogavare yelling and screaming in parliament. He can lose his cool sometimes."

Sogavare's next tilt at power came in similarly tumultuous circumstances in 2006.

Post-vote rioting in the capital Honiara forced prime minister Snyder Rini to abandon ship after just eight days.

Again, Sogavare was on hand to pick up the pieces. He was elected for his third and fourth terms in 2014 and 2019.

- 'Master of Mayhem' -

Fed up with a political class widely seen as corrupt -- and unnerved by the sudden lurch towards Beijing -- rioters tore through Honiara's Chinatown after Sogavare's 2019 victory.

Violence returned in 2021, when angry mobs tried to storm parliament, torched much of Chinatown and attempted to burn down Sogavare's home.

Although a fierce nationalist, Sogavare holds a particular soft spot for Winston Churchill -- peppering his speeches with references to the British wartime leader.

New Zealand academic Jon Fraenkel earlier this year described Sogavare as the country's "master of mayhem".

In his efforts to keep the lid on bubbling discontent, critics fear he has developed increasingly autocratic tendencies over the years.

Sogavare has threatened to ban foreign journalists, Facebook, and diplomats.

"He's learned a lot in his time as prime minister," said Moore.

"He's learned how to control power, and how to handpick key positions in the public service."

- Assassination plots -

Sogavare harbours a deep distrust of Australia and the United States, traditionally two of Solomon Islands' closest security partners.

Australian peacekeepers were deployed to Solomon Islands from 2003 to 2017, spearheading rebuilding efforts after ethnic violence left the nation on the brink of total economic collapse.

But Sogavare resented the intervention, believing the Australians were trampling over his nation's sovereignty.

An already testy relationship curdled completely in 2006, when Australian police raided Sogavare's office while he was out of the country.

They were looking for evidence as part of a botched investigation into Sogavare's former attorney general, accused of child sex crimes.

Further inflaming Sogavare's misgivings, local media have over the years carried a series of barely credible reports about US and Australian kill teams plotting to assassinate the leader.

The United States last year dismissed the latest round of unsubstantiated reports as "deplorable" disinformation and smears.