IN a glass palace more akin to a boutique hotel than a City law firm, Peter Cornell makes his case.

“I certainly recognise that the last two years have been tough,” he says, “and we have had issues to deal with” — he pauses a beat for dramatic effect — “but we are working our way through them.”

Cornell, a lean, beaky charmer of a boss, would have made an amiable barrister. Instead, he has run Clifford Chance, the world’s biggest law firm, since 2002.

In that time, the firm — a limited-liability partnership with 3,300 lawyers, £950m turnover and 29 offices worldwide — has reinforced its global superiority, but garnered the sort of bad press that would have dented many other organisations: bust-ups in America and Europe over pay, partners defecting at an unprecedented rate, rumours that profitability and morale are slipping.

Being big is never easy. The origin of Clifford Chance’s recent troubles, suggests Cornell, was the double merger in 2000 with law firms in America and Germany that turned it into the world’s largest. The fit has proved problematic, especially in America, where Clifford Chance’s new colleagues blanched at the low British pay scales.

To some of the firm’s rivals, particularly others in Britain’s “magic circle” of big law groups (Allen & Overy, Freshfields, Linklaters and Slaughter and May), it still looks as if Clifford Chance bit off more than it could chew.

But Cornell, 52, the managing partner who has to make it work, is not inclined to be gloomy. Striding round his spacious first-floor office in Clifford Chance’s extraordinary base in Canary Wharf — a glass skyscraper with a designer foyer the size of half a football pitch — he quickly accentuates the positive.

Being big is going to be a real advantage with global clients, he stresses. The internal issues are settling down now, and Clifford Chance, which has governments, banks and leading multinationals among its clients, does a lot of things really well, not least opening its doors to the widest range of people.

In fact, it prides itself on being the least snooty and most meritocratic of the big City law firms because of its roots in two smaller outfits, Clifford-Turner and Coward Chance. They barged their way into the magic circle by merging in 1987 and made themselves pre-eminent in servicing international banking and finance giants.

“We’re pioneers. We’ve got the brainboxes but we are less establishment, too, and that’s a source of pride,” says Cornell. “It’s about putting quality first. If somebody is good, it doesn’t matter if they don’t have the right labels.”

In a week when a British government minister criticised the top firms for their persistent discrimination in favour of Oxbridge graduates, that might count for something.

And in Cornell (a graduate of Exeter University and resident in Madrid, where he is a neighbour of the Beckhams) Clifford Chance has the least snooty and most gregarious of bosses. On first meeting him, you would be hard-pushed to think he was a lawyer. Tall, chatty and outgoing, with ready humour and an avid interest in others, Cornell seems more like an accomplished account handler in advertising than the most powerful lawyer in the world.

But he trained as a finance-law specialist and used to run Clifford Chance’s European network before accepting the top slot. More important, he was voted to the top by the firm’s partners because he has uncommon people skills. His brief: to organise, conciliate and enthuse a bunch of executives — big-earning lawyers — who must be among the brainiest, most pedantic, hardest-to-lead workforces in the world.