Written question asked by Alex Burghart (Conservative) on Thursday, 10 September 2026, in the House of Commons. It was due for an answer on Monday, 14 September 2026. It was answered by Uma Kumaran (Labour) on Friday, 18 September 2026 on behalf of the Foreign, Commonwealth and Development Office.

Chagos Islands: Sovereignty

Question: To ask the Secretary of State for Foreign, Commonwealth and Development Affairs, with reference to the Answer of 8 January 2026 to Question 101383, on Government Actuary's Department: Freedom of Information, if he will ask the Government Actuary's Department to update the Chagos calculation chart further to the change in the social time discount rate announced by HM Treasury on 7 September 2026.

Answer: The value of payments under the UK-Mauritius Agreement were set out by the UK government at the time of signature and have not changed. What has changed is the Social Time Preference Rate applied in the calculation of the forecast net present value, which applies to all long-term government investments of this nature. The chart was produced to calculate the forecast costs of payments under the Treaty at the time of signature. The forecast real value of payments remains £101 million per annum in today's money. There are no plans to ask the Government Actuary's Department to update the chart.

Secondary information

Type: Written question
Reference: 28802
Session: 2026-27
Related items: Government Actuary's Department: Freedom of Information
Thursday, 8 January 2026
Written questions
House of Commons; Chagos Islands: Sovereignty
Wednesday, 21 October 2026
Written questions
House of Commons
Transferred: Yes
Subjects: Finance Government Actuary's Department Mauritius Sovereignty Chagos Islands
Link: View this Written question on www.parliament.uk