Why the Royal Mail privatisation has been controversial
Tuesday is the last day for people to express their interest in buying Royal Mail shares, which are likely to cost more than was originally intended because demand has outstripped supply.
Dr John Glen from Cranfield School of Management told BBC Breakfast they would be "about £3.30 a share" but shareholders would "get a return of about 6.5%".
Shadow business secretary Chuka Umunna has said the sale is "short changing" taxpayers.
Dr Glen explained why it has been controversial: "Over the last six years, we the taxpayers have spent about £2.75bn making the Royal Mail more profitable, we've taken on £8bn of pension liabilities... and of course there's the issue about whether or not the Royal Mail will guarantee to deliver to us every day, across the whole country, at a single price."