Former heads of Government are supposed to disappear quietly into retirement. But Tony Blair doesn't care for obscurity.

Instead he's in Dublin this weekend promoting his just-released autobiography, ‘A Journey', which is selling in numbers normally associated with a Harry Potter book.

It's no coincidence that Tony Blair chose Ireland to kick off the limited promotion of his book; here he (rightly) gets kudos for his crucial role in the Northern Ireland peace process, while in Britain he gets a far frostier reception over his decision to involve the UK in the war in Iraq.

And yesterday in the Shelbourne Hotel it was clear that the former Prime Minister had lost none of his zest for being back in the public eye.

Dressed casually in jeans and a blue shirt, he looked tanned, relaxed and fit as the proverbial butcher's dog. “I'm probably working harder than I've ever worked now, and I don't feel in the least retired,” he explained.

Sipping strong coffee to carry him through an evening of rapid-fire interviews, Tony exuded positivity.

He had nothing but high praise for Bertie Ahern who he describes in the book as one of his favourite political leaders.

“I got on with Bertie extremely well. He was just incredibly brave in the positions he took.”

One of the most absorbing chapters in the autobiography is where he details the hammering-out of the peace process, and how he bonded with Ian Paisley over discussions on their deep faith.

And yet he waited until after he left office before joining his wife Cherie's faith and converted to Catholicism.

“I was gong to Mass all the time I was Prime Minister . . . It's a personal thing and I knew if I did it while I was in office it would be treated as some great political statement I was making and it wasn't — it was a personal decision, it was where I felt at home,” he explained.

The trademark Blair upbeat attitude also refuses to allow him to regard the Iraq war as a blot on his legacy.

“I think in the end these things play themselves out and people take a rounded view, and also it's too early to tell in respect of Iraq.

Let's wait and see what happens, there's a lot still in this whole wider issue to deal with extremism in the world and how we deal with it.”

But surely it can't be pleasant to be accused of having blood on his hands as a result of siding with the decision of George W Bush to go to war on Iraq?

“It's not nice, and you don't like it, but at the same time you can't let it disrupt you, because one of the things that I learned in politics is that those who shout loudest aren't necessarily the ones whose voices should be heard most,” he shrugged.

“I mean, read part of the British media today, you'd think I hadn't won three elections.

“I mean I won them, I didn't lose them,” he added with a defensive laugh.