Blair first guest on Sky's new show

Mr Rubin, who will be one of the channel's star political commentators, has pledged not to "joust" with politicians in the adversarial style favoured by Jeremy Paxman and John Humphrys.

In the first of his regular World News Tonight weeknight slots discussing international affairs on the revamped news channel, Mr Rubin will interview Tony Blair tonight. The interview, however, will take a very different tone to the grilling Mr Paxman subjected the Prime Minister to in the run-up to the general election earlier this year, when the Newsnight presenter asked Mr Blair 20 times to estimate the number of illegal immigrants in Britain.

Mr Rubin, who worked with Blair during his time as an assistant secretary of state in the Clinton administration, said: "I'm not a jouster. I'd like to think we'd have an intelligent discussion about the big issuess of the day, Iran and Iraq."

Asked whether he intended to follow in the footsteps of Mr Paxman and Mr Humphrys, he said: "I have no problem with those guys. They can do whatever they want. They have their own roles in the media business. It's not what I aspire to."

There's a place in journalism for people who give the Government a hard time. I don't pretend that I will become that kind of journalist."

While he has presented a documentary series for the US public service channel PBS and guest-hosted the BBC's Hard Talk, it is the first time the former government spokesman has presented his own television show.

Mr Rubin said the show, which he will present from Sky News's new, state-of-the-art studios, would be "Western but international"

He has made no secret of his concerns that the Arabic news channel al-Jazeera skewed its viewers' attitudes towards the US.