Chagossian islanders have launched a legal battle in the High Court to block the handover. On 22 May 2025, two Diego Garcia-born women, Bernadette Dugasse and Bertrice Pompe, sued to stop the plan. Chagossians fiercely oppose the handover, feeling their voices have been "sidelined" and branding their homeland a "bargaining chip". Many, holding British citizenship but not Mauritian, distrust Mauritius and fear discrimination, haunted by past poverty there. The deal also lacks firm guarantees for their return to the islands, crushing their hopes, particularly with Diego Garcia being off-limits. Viewing their eviction as a "crime against humanity," Chagossians demand reparations and apologies, fearing the handover allows Britain to dodge accountability. Some 10,000 Chagossians, scattered across Mauritius, the Seychelles, and Britain, vow to "fight on" for self-determination and justice.

Conservatives have unleashed a barrage of criticism, accusing Labour of "selling out British interests" and "betraying the UK". Key criticisms from Conservatives, including MP Tom Tugendhat, include the "strategic risk" to the Diego Garcia UK-US military base which underpins UK-US dominance and global clout, questioning the security of long-term base control. Some have "baselessly claim[ed]" Mauritius could fall under Chinese influence, "jeopardling fears" of compromised base security. They also question the value to taxpayers of the deal's £1.01 billion annual lease cost (£34 billion over 99 years, inflation-adjusted).

The critical UK-US military base on Diego Garcia lies at the heart of the row. The base was established after Britain detached the Chagos Islands from Mauritius in 1965 to form the British Indian Ocean Territory (BIOT). Britain leased the island to the US in 1966 for 50 years (extended to 2036). The proposed handover deal includes securing a 99-year lease for the base.

The article provides historical context, noting the islands' colonial history under French and then British rule. Between 1967 and 1973, approximately 1,500 to 2,000 Chagossians were forcibly evicted using "brutal tactics" to make way for the US base, leading to their decades-long fight for return and reparations. The plan is backed by a 2019 International Court of Justice (ICJ) ruling deeming UK control unlawful and a UN resolution urging return.

Labour counters that the deal aligns with international law, secures the base, and advances decolonisation. Prime Minister Keir Starmer insists the move "rights a historic wrong". Although Starmer signed the handover treaty on 22 May 2025, a High Court injunction triggered by Chagossian lawsuits briefly halted progress. Though lifted, the transfer date remains unset, pending legal and international hurdles. The saga is described as weaving colonial guilt, Chagossian rights, and superpower strategy, leaving the future "shrouded in uncertainty".