The UK Statistics Authority wrote to James Cartlidge MP about Chagos Islands deal

4 July 2025 · Sir Robert Chote, Chair, UK Statistics Authority

The letter, dated 4 July 2025, replies to correspondence of 23 May 2025. The UK Statistics Authority published it as Letter from Sir Robert Chote to James Cartlidge MP – Chagos Islands deal; it links to 2 official records. Below are 4 passages from the letter in the regulator's own words.

What the UK Statistics Authority wrote

“But given the Government’s reference to the Office for Budget Responsibility (OBR) in defence of its chosen figure, we have confirmed with the OBR that they believe that this is a reasonable one to use when discounting the value of a lease.”

“Our one concern is that by describing the £3.4 billion figure as the net overall cost, it was not made clear to the public that the figure was calculated using a discounting method.”

“In future, we would encourage a link to this explanatory memorandum to be provided within the press statement in order to better support the public in understanding and scrutinising the figure.”

“We welcome that this information was made public at the time of the press statement in line with the principles of intelligent transparency.”

From Sir Robert Chote, Chair, UK Statistics Authority, letter of 4 July 2025. Read the full letter.

The words the letter quotes

The letter quotes 1 passage from the public record:

“£101 million a year is the average cost; the net overall cost is therefore £3.4 billion overall, that’s over the 99 years”.”

Records the letter links to

• the explanatory memorandum
• the press statement

Correspondence

• The letter it answered: James Cartlidge MP to Sir Robert Chote – Chagos Islands deal (23 May 2025)

More on James Cartlidge.

Receipt