Steve appears to have been sharper than me on this. I also received the UK Statistics Authority’s reply today (exact same wording). My response was:
“I note with concern that this means the Prime Minister expects to put nearly £10 billion into the NHS over the next two years, when in the last three he has taken nearly £1 billion away (and I am unsure whether that includes amounts exceeding £1 billion that the Treasury clawed back from NHS budgets over this period)!
“He will need to be monitored constantly and I trust the UK Statistics Authority will continue to do so. Failure to fulfil his promises – for whatever reason – will require a strong public rebuke, to match the amount of exposure he has given to his claim.”