A tiny, almost barren island in the Indian Ocean has become a battleground in this weekend's elections in Seychelles, prompting global environmental concern.

Assumption Island, in the western Indian Ocean, possesses little at first glance that would set even the most curious and intrepid traveller's pulse racing. Stripped almost bare and blisteringly hot, with few man-made structures, it covers an area similar to London's Heathrow Airport and is, arguably, only slightly more scenic.

Yet this tropical island anomaly - both geographically remote, and far from the popular ideal of lush paradise - has become a hotspot for geopolitical powers and eco-warriors, plus a political lightning rod in Seychelles, the country that owns it.

Situated 1,140km (700 miles) from Seychelles' most populous main island, tourist-friendly Mahé, Assumption Island is a sausage-shaped, coralline finger of low-level scrub, fringed by casuarina trees. It was ravaged for its nitrogen-rich guano (seabird droppings) and agricultural use ended decades ago. But now, Assumption Island's strategic position and ecological value is priceless.

The island lies close to this century's Silk Road – the busy commercial shipping lanes carrying manufactured goods and materials from East Asia to Africa and beyond. India was keen to build a military base on Assumption but was rebuffed. Permanent or de facto ownership has so far been off the cards thanks to pressure from the proud Seychellois public. As the tiny republic goes to the polls in presidential and parliamentary ballots, Assumption is a key electoral touchpoint.

At least under my watch, there will never be a foreign military base in Seychelles, President Wavel Ramkalawan tells BBC News, on the eve of polling. We are not interested in the geopolitics. We remain outside.

The lease of Assumption Island, or at least part of it, to the Qatari royal family has stirred sensitivities. Via a Middle East investment company, Assets Group, the Qataris are currently building an exclusive, 40-villa luxury resort there, with an upgraded concrete airstrip capable of receiving executive jets, far from prying eyes.

Assumption has one of the longest beaches in Seychelles, which is probably one of the most important green turtle nesting beaches in our country, says conservation campaigner Lucie Harter. It's a really important place to preserve.

Crucially, Assumption Island is the gateway to the Unesco-listed Aldabra atoll, just 27km (17 miles) to the north. One of the most pristine and fragile ecosystems in the world, Aldabra is home to 400 species found nowhere else on the planet. Sir David Attenborough described it as one of the world's greatest natural treasures.

But noisy neighbours risk disrupting nature's delicate equilibrium.

Ramkalawan, an ordained Anglican priest who signed the deal with Qatar last year, is unrepentant. He is quick to point out that remote Seychelles, with a population of just over 120,000, faces unique challenges. The Assumption lease, entailing Qatari occupation for 70 years with a $20m (£15m) down payment, was a simple calculus.

What's wrong with it? he asks. We have all those Hilton hotels. The Qataris are bringing in [luxury hospitality operator] Rosewood as the hotel company that will be running it. We've got to look for investment in order for us to survive.

This weekend's elections may deliver a clearer sense of whether or not good governance, transparency and accountability will be prioritized by the voters, especially in light of the controversies surrounding Assumption Island.