In a treaty to “complete the process of decolonisation of Mauritius” the British Government has agreed to pay at least £120 million-a-year for 99 years for control of the vital Diego Garcia military base, plus hand over £1.125 billion for economic development over a 25-year period.

Britain signed a multi-billion dollar deal on the future of the Chagos Islands with Mauritius after a last-gasp injunction was overturned, securing itself a lease for the U.S.-UK Diego Garcia air base for the next century.

A British court on Thursday paved the way for a government deal on returning the remote Chagos Islands to Mauritius, lifting a temporary ban which had forced an 11th-hour halt to an accord being signed .

Mauritius and Russia have agreed to strengthen ties, amid fears that the UK was too hasty in deciding to hand over the Chagos Islands.

The decision to return the islands at a cost to the UK has been made amid welfare cuts and calls to prioritise domestic spending.