The Business On... Dido Harding, Chief executive, TalkTalk

I thought that chubby bloke was in charge?

You presumably mean Charles Dunstone, who founded the company. He's not been in day-to-day control since last year when thebusiness was divided into TalkTalk, a broadband provider, and Carphone Warehouse, the retailer. Ms Harding was hired to run the former.

So what has she done so far?

She's been pretty bold. Though Mr Dunstone remains chairman of the company, Ms Harding announced yesterday that she is ditching his strategy, which was always to chase ever greater numbers of subscribers. She wants to concentrate on cost, efficiency and getting the most from existing customers.

Does she know what she's doing?

Let's hope so for TalkTalk's sake. But her track record in business suggests we should trust her. She was a high-flying executive at Tesco before Sainsbury's poached her a few years ago to head up its convenience store network. Her stint at the retailer, where she sat on the board, saw her marked out as a potential future chief executive, and then TalkTalk swooped.

She's a smart cookie then?

Indeed: educated at Oxford and Harvard, she started out at themanagement consultancy McKinsey, where she met her husband John Penrose. He's now the Conservative MP for Weston-super-Mare.

So she married well?

Actually, he did. Ms Harding may not use the title, but we ought really to be calling her the Honourable Diana Harding. She's the daughter of Lord Harding.

But they're a power couple?

It looks that way. Ms Harding's star is on the rise and so is Mr Penrose's – he's now a junior minister in the Department for Culture, Media and Sport, where his responsibilities include the horseracing industry. That's rather appropriate: Ms Harding is a former amateur jockey who is still in love with the sport. She owns Cool Dawn, the winner of the 1998 Gold Cup.