His peers on Piers

Friends and foes of Piers Morgan speculate on how he'll fare in the US

Piers Morgan makes his CNN debut tomorrow in the first airing of his US chat show, Piers Morgan Tonight. It's a move that has caused intense speculation – not least because he takes the mantle from Larry King, widely regarded as America's premier broadcast interviewer since 1985.

Some will be watching to see whether the pugnacious former Daily Mirror and News of the World editor can succeed in winning over American audiences. Others will salivate at the prospect of him falling on his face or alienating celebrities. Before he even started, Morgan last week described Madonna as "an irritant in my life for 20 years".

His challenge, say pundits, is to "break" Oprah Winfrey, his first guest, as he "broke" Cheryl Cole, who sobbed when she recounted her split with her husband Ashley Cole; or Gordon Brown, who wept as he talked of the loss of his daughter to the most unlikely of confidants. Subsequent guests include Howard Stern, Condoleezza Rice, Ricky Gervais and George Clooney.

Morgan's pursuit of fame across the seas seems a natural progression, born of a friendship with Simon Cowell and appearances on Britain's Got Talent, America's Got Talent and the celebrity Comic Relief version of The Apprentice. But he's known his share of controversy – he was investigated after the Viglen share-tipping scandal in 2000, and sacked from the Daily Mirror in 2004 for publishing hoax photographs purporting to show Iraqis being abused by the British Army.

According to the man himself, whether or not he'll be a hit comes down to the Marmite test. "You love it or hate it," he has said, before adding, cheerfully, that those who hate it will consider him to be a "ludicrous, arrogant twat".

Celia Walden

The writer married Morgan last year

"I'm in the studio when a crew member comes up to me. 'I knew this was going to be a slightly different show when I heard your husband ask Condoleezza earlier: "Hypothetically, Dr Rice, if I was going to seduce you – how would I set about it?"' I feel I should apologise for his behaviour, but if I start doing that now, I can't see I'll ever stop."

Cameron Jones

Outgoing first team captain at Newick Cricket Club, East Sussex

"Newick is a bolt-hole for him. He was involved in the club as a junior, and if you ask Piers, he'll say he's a fantastic player – but he's not as good as he thinks he is! He gets very involved; Celia's pulled pints at our social and he's brought celebrity guests, including Kevin Pietersen and Jerry Springer, to play here. He's just one of the guys – we make sure he stays grounded."

Andy Cooper

Editor of the North Devon Journal, trained with Morgan at Harlow College

"We always knew him as Harry, because no one could get their head around having someone on our course called Piers Pughe-Morgan. He was the life and soul of the course. He lived with a woman who had ulcers on her legs, who he called 'The Leg', and made us laugh. He did what everybody did – got drunk, fell over and made up stories."

Nicky Cox

Editor of children's newspaper First News, of which Morgan is the executive editorial director

"We met at the Wimbledon News – one of his first jobs – while I was on work experience. Then I worked at the BBC, and he was at The Sun. We were celebrating people like Take That, while he was having a pop at them, so we coined the nickname 'Piers Moron' in Top of the Pops magazine. He's arrogant, but his tongue is firmly in his cheek."

Anil Bhoyrul

Former Daily Mirror business journalist, investigated along with Morgan and James Hipwell over the City Slickers Viglen share-tipping scandal

"I've known Piers for 20 years. The last time I saw him was at my wedding. My mum spent eight years wanting to give him a piece of her mind, but then she met him and was completely charmed. That's what he's like – you'll never find anybody with a bad word to say about him. What happened, happened. I blame myself, to be honest."

Max Clifford

Says Morgan once described him as the 'first person he'd call' if he was in trouble

"I introduced him to Simon Cowell and that's what made him: the rest is history. We've had our disagreements, but he never takes himself too seriously. It's going to be bloody hard for him in America. Simon had to learn how to handle American audiences, and, if he wants to be successful, Piers will have to do the same."

Stuart Higgins

Former rival editor at The Sun

"When we were head to head at The Sun and the Daily Mirror, there was a fierce rivalry in probably one of the biggest circulation wars of the tabloids. He is an uncompromising competitor in everything he does. He's desperate for the first global interview with Prince William and Kate Middleton and is aiming high from day one with President Obama."

Polly Graham

Former 3am girl at the Daily Mirror

"He was a brilliant editor and fun to work with. He gave us pep talks: 'I want you to go out until 3am, catch celebrities behaving badly, and I want people to be writing stories about you.' He had madcap ideas – one time he banned people who complained about the press from the front pages. He's massively egotistical but endearing with it."

Kelvin MacKenzie

Former Sun editor, employed Morgan to write the Bizarre column

"We occasionally see each other, and we text – which is the only relationship you can really have with Piers because he's so busy. He's out of the country roughly nine months in a year. He's got what all successful people have – energy and enthusiasm, or 'E squared'. Piers' 'E squared' is phenomenal. If the show doesn't work, it won't be anything to do with Piers."

James Hipwell

Former Daily Mirror business journalist, investigated along with Morgan and Anil Bhoyrul over the City Slickers Viglen share-tipping scandal

"His interview subjects are often beguiled by his monstrous charm. It's why the likes of Nick Clegg fall into his trap and end up saying foolish things like he slept with 30 women. It's the matey, 'I'm a friend of the stars' approach that he tried to get Anil and me to adopt when we were doing City Slickers. Can't think of much more to say about the arsehole, to be honest."

Oprah Winfrey

The chat show queen is the first guest on Morgan's show 'Piers Morgan Tonight'

"He is a tough cookie. Those days of Larry King softballing you... over, baby! Listen, I had to take a hot bath and a couple Anacin after that interview. It was like volleying. You have to be on your toes and think, 'That is the same question and you just phrased it a different way.' He's tough."

Lord Sugar

Famously sparred with Morgan on Twitter to see who could get the most followers by Christmas Day 2010

"I met Piers in 1993 when he was the editor of the Mirror. He came to my 40th wedding anniversary and got a little inebriated. I gave him his big TV break on celebrity Apprentice – though I had to fire him. Piers is all right – he's direct and confrontational but a decent bloke. The challenge is what the American public will make of him. He's going to have to earn his wings."

Alastair Campbell

The former spin doctor has revealed his and ex-PM Tony Blair's thoughts on Morgan in his diaries

"Friday 20 March 1998: Despite my anger at the Piers Morgan interview being about anything other than the budget, he did five pages and it was OK. TB said he was basically a slug but he was clever, and we shouldn't over-alienate or underestimate."