Responding to a question in the House of Commons this week, Exchequer Secretary David Gauke said that recent research suggests that the ebook market in the UK was worth approximately £140 million in 2011. However, he also admitted that the Treasury has no idea how much tax it collects on these sales.

Gauke said: "A large proportion of this business is supplied from abroad. Therefore, no reliable estimate has been possible for the value of VAT levied on the sale of e-books purchased in the UK."

eBay also came under fire recently for only paying 0.15 percent of tax on sales worth some £798 million in the UK during 2010. An investigation by the Sunday Times found that the £1.2 million tax bill fell substantially short of the £51 million it would have paid if it had followed standard corporation tax guidelines.