Mr Blair won the support of the Murdoch papers ahead of his election victory in 1997, and he has maintained a good relationship with those high up in News Corporation ever since.
Blair is also the godfather of Rupert Murdoch’s daughter Grace.
However, Lord Mandleson, who held a key role in the building of “New Labour”, denied that there was any kind of pact between the Blair Camp and News Corps.
The link between Blair and Murdoch first came into public view in 1995, when the then Labour leader headed to Hayman Island in Australia to address News Corps executives. It was part of his attempts to the newspapers which had unfavourable portrayed party leaders Michael Foot and Neil Kinnock.
Blair’s former press secretary Alastair Campbell has previously told the enquiry, "I never was witness to, and I do not believe there was ever a discussion that said, 'now, Tony, if you do this and do this my papers will back you' - it just never happened."
He was also asked about three phone calls between Blair and Murdoch that took place shortly before the 2003 invasion of Iraq, dismissing suggestions that Mr Blair could not have pursued his defence policy without the backing of Mr Murdoch and the Sun.
Other politicians set to be questioned by Lord Leveson this week include Education Secretary Michael Gove, Home Secretary Theresa May, Business Secretary Vince Cable, Justice Secretary Ken Clarke, as well as beleaguered culture secretary Jeremy Hunt.