Parliamentary Voting System and Constituencies Bill

Can my right hon. Friend shed any light on the latest budget for the referendum? I believe that before the election the Government made it clear that the referendum would cost £40 million. On 27 July, the hon. Member for South West Devon (Mr Streeter) said it would cost £9.7 million, representing a saving of £17 million, because it was being held on the same day as the other elections. On 18 August, the Deputy Prime Minister told the press that it would cost between £80 million and £100 million. Can my right hon. Friend shed any light, or are we just looking at a random selection of numbers?