Murdoch, the son of News Corporation magnate Rupert Murdoch, resigned his post in February, as damaging revelations about his newspapers continued. Mr Murdoch senior will be appearing in the enquiry tomorrow.

James Murdoch was head of Corporation’s UK branch, and effectively ran The Sun, The Times and the now-closed News Of The World, formerly one of the most famous newspapers in the world.

It is thought that the Murdochs will be asked if they were aware that the practice of phone hacking had gone beyond News Of The World royal reporter Clive Goodman, who was jailed in 2007. The Murdochs told a Commons enquiry last year that they had no idea of the scale of wrongdoing at the paper.

In 2008, James Murdoch was copied into an email that talked of “rife” phone hacking at the newspaper. However, James Murdoch claims that he did not read this email in full.

Earlier in the week, the focus at the Leveson Enquiry was on the close relationships between newspaper owners and politicians.  Evgeny Lebedev, the owner of the Independent and Evening Standard, said the relationship had been “overestimated” and that he had only met David Cameron four times in total.

However, chairman of the Telegraph Media Group, Aidan Barclay, said it was the duty of  "most businessmen to get to know the politicians that make rules and regulations that affect their business".

Meanwhile, head of Sky News John Ryley admitted to hacking emails, but that the end justified the means. They hacked the emails of John Darwin, the “canoe man” who faked his own death and started a new life with the insurance money.