Leading article: Questions for Mr Blair to address

An appearance at the Leveson Inquiry holds fewer obvious pitfalls for Tony Blair than his grilling by members of the Iraq inquiry. But the answers given by the former Prime Minister today should prise open the window a crack further on his government's relations with the media, and with one media baron in particular.

After all, it is with Mr Blair's readiness to fly half-way around the world to meet Rupert Murdoch at Hayman Island when he was still in opposition that the tycoon's hold on Britain's political class was made manifest.

There are, as we report today, a clutch of questions for Mr Blair to answer, not just about why he deemed that first meeting so necessary, but about the relationship with Mr Murdoch as it developed through his time in office, and at what point it graduated from business to personal – as it appears to have done, given that Mr Blair (secretly) became godfather to one of Mr Murdoch's children. The baptism on the banks of the river Jordan is among the more colourful episodes in Mr Blair's now varied career.

A running theme of this part of the Leveson Inquiry has been the closeness between Mr Murdoch and his UK executives on the one hand, and successive prime ministers on the other. While both parties have been shy about any benefits derived, it is possible to discern a subtle shift in power, as Mr Murdoch turned from courtier into the one to be courted. Was that shift, perhaps begun in 1992 with The Sun's claim to have been "wot won" the 1992 election for John Major, completed by Mr Blair?

The central question Mr Blair has to answer concerns what undertakings might have been given to Mr Murdoch – or perhaps understandings reached – in return for The Sun switching its support to Labour. Mr Cameron, by the way, should face a similar question relating to 2010. But Mr Blair should also be quizzed about any changes in his government's views on the regulation of media ownership and how it was that all News International newspapers came to support the Iraq war. As the first prime minister to set so much store by media-management, Mr Blair should have some telling insights. We just hope his memory does not fail him.