J-Lo tells diamond bosses: I'm not your best friend

* The new Leonardo DiCaprio picture Blood Diamond is an action film unrelenting in its violent portrayal of Sierra Leone's 1990s civil war, and the western diamond industry's role in prolonging the conflict for profit.

DiCaprio's co-star Djimon Hounsou (Gladiator) has an Oscar nomination for Best Supporting Actor. At the Leicester Square premiere, he told Pandora: "I can tell you why we didn't make this film: we didn't make this film to stop people buying or wearing diamonds.

"We made this film to highlight how western corporations are doing business in Africa."

The diamond industry is running scared. Ethical business campaigners talk of a "$50m PR offensive" (the figure is inflated). On Monday, it was reported that the singer-actresses Jennifer Lopez and Beyoncé Knowles agreed to brandish diamond rings for the cameras at last week's Golden Globes, in return for $10,000 diamond industry donations to African charities of their choice.

I hear that Lopez's camp furiously deny the report is accurate. J-Lo is said to be miffed because her own "morality movie" about human rights on the Mexico border, Bordertown, premieres in February.

Lopez is moving to distance herself from the row and from any diamond promotions. Her manager has told Amnesty International that Lopez has no interest in promoting diamonds.

"She's bloody angry," says an Amnesty source. "Her manager insists Lopez isn't working for the diamond industry and won't be."

* Lord Andrew Lloyd Webber unveiled his latest protégé Andrea Ross at the West End nightclub Paper on Tuesday.

Lloyd Webber, champion of Elaine Page, Sarah Brightman and, last year, Connie Fisher, stumbled across the 15-year-old singer from Boston, Massachusetts, when his PA passed him a "tinny karaoke tape" two years ago.

The theatre mogul is mentoring Ross and has produced her forthcoming album Moon River. He also appears to be matchmaking between Ross and his teenage son.

"Andrea is becoming a bit of a rock roller and is writing songs with my son Alastair who's 14 at the moment," he tells me. "So who knows where that's going to go!

"They're making pop songs. We invited Andrea over for dinner and she was forced into the playroom for a demo session."

Ross tells me: "School aren't too happy, but I get the time off to perform."

* The British film Notes on a Scandal scored a marketing coup in Beverly Hills on Tuesday by bagging Oscar nods for the screenwriter Patrick Marber and actresses Judi Dench and Cate Blanchett. Alas, the momentum will be lost at the London premiere this weekend: none of the stars will turn up. Prior engagements prevent Marber, Dench, Blanchett and Nighy from attending.

Blanchett is in New Orleans on Brad Pitt'sThe Curious Case of Benjamin Button. Nighy is onstage in New York in David Hare's The Vertical Hour. Dench is in Stratford with the RSC.

It's a public relations half-volley into an open goal gone begging, since glitzy Sunday premieres are near-guaranteed coverage in Monday's slow news pages.

Good luck to 'em anyway.

* Tesco's expansion will not end until it has built a Tesco Metro on the side of the White Cliffs of Dover. Maybe never.

News reaches Pandora from Potters Bar that Sir T Leahy (aka Terry, chief exec) received planning permission to extend his Hertfordshire mansion - despite objections from the parish council that "this is a large extension to a substantial house in the green belt... contrary to guidance".

The Tesco boss placated planners by promising not to build a roof over his existing outdoor swimming pool.

A gracious gesture by a fine man, and the sort of leadership this country dearly craves from its captains of industry.

* I hear of a new weekend guest at Chequers, the country residence of the famous Newcastle United Football Club supporter Anthony Blair. Added to the roll call of luminaries to have broken bread with the current PM (Sir Elton, David Bowie, Mick Hucknall, Bono, Sting, Bob Geldof, Richard and Judy, Star Trek's Patrick Stewart and Geri Halliwell's pet shih tzu Harry, who disgraced himself on the carpet) is... the England football manager Steve McClaren.

Both Blair and McClaren know how it feels to sit in the shadow of a P45, be betrayed by treacherous underlings and see lurid tales about their private life litter the press. I rang the Football Association to find out if McClaren enjoyed the lobster thermador starter, but he was unavailable - he was actually at the House of Commons for Prime Minister's Questions yesterday, at the invitation of Labour MP Alan Keen.

Says my mole at Chequers: "They spent the entire weekend talking about how they don't read the newspapers."

pandora@independent.co.uk