"These are very, very ambitious ideas and the Conservative Party have their own ambitious idea for full fibre for everyone by 2025 and how we do it is not straight forward," Chief Executive Philip Jansen told the BBC.

"It needs funding, it is very big numbers, so we are talking 30 to 40 billion pounds.. and if you are giving it away over an eight year time frame it is a another 30 or 40 billion pounds. You are not short of 100 billion pounds."

(Reporting by Andrew MacAskill)