Who's who?

"It's their Murdoch hearing" commented one select committee chair, pondering today's Treasury Committee hearing (at 2pm) with the ex-boss of Barclays, Bob Diamond.

Once again we have a master of the universe, at the epicentre of a scandal, appearing before a committee of MPs. But will we see the forensic pursuit of the truth, a clash of competing political agendas - or a determined attempt to play to the media gallery? Probably a bit of all three.

So who are the MPs who'll be asking the questions? Here's my cut-out-and-keep guide to the Treasury Committee:

In the chair is the Conservative Andrew Tyrie - former special advisor to Nigel Lawson in the heyday of Thatcherism, which means he was one of the team behind deregulation of the City of London. He was the surprise winner in the elections to chair the committee, defeating Michael Fallon for the post. He has a reputation for independence and has not been afraid to take on David Cameron when the PM appeared before the Commons Liaison Committee, and has pursued campaigns on issues like rendition of terrorist suspects.

Having been asked to chair a special parliamentary committee to investigate the banking system, he's been caught in the crossfire between the government and Labour over whether that inquiry should be judicial or parliamentary. He's too smart to stage an elaborate display of independence, to press the case for his heading the investigation; he will probably feel that the best way to persuade opponents is to extract genuine answers from Mr Diamond.

What of the committee members?

MP most likely to ask a really clever question is Pat McFadden. Tony Blair's former political secretary has a manner so low key that it's almost subterranean, but don't be lulled - he combines a very sharp political brain with extensive experience as a trade minister. None of the Labour MPs on the committee have a City background but he is least likely to be baffled by the intricate technicalities of City trading.

MP most likely to bowl a googly: John Mann. A Labour maverick who once asked a witness at the Treasury Committee to explain why it was easier for a camel to pass through the eye of a needle than for a rich man to enter the kingdom of heaven. He specialises trying to destabilise witnesses with completely unexpected lines of questioning, often delivered with aggression or derision, or both. He may run a tag team with George Mudie, a heavy metal ex-whip and former leader of Leeds City Council. Like John Mann, he has a track record of attacking "fat cats". He served on the joint committee which scrutinised the Financial Services Bill, before it was fed into the parliamentary machine.

Danger men: Michael Fallon - another Tory heavyweight, a former minister and a long standing member of the Treasury Committee. He is now deputy chairman of the Conservative Party and regularly bats for the Tories on TV and radio. He is one of the committee's toughest interrogators. Also watch David Ruffley: like Andrew Tyrie he's a former special advisor to a previous Conservative chancellor, Ken Clarke. He has already taken a tough line against other banking executives - campaigning for Fred Goodwin to be stripped of his knighthood because of his stewardship of RBS. He is likely to zoom in on Barclays' discussions with the Bank of England at the time of the rate-fixing. Was there a "nod and a wink" from officials, or is that claim simply intended to divert the blame?

Serious experts: Andrea Leadsom - tipped as a (near) future minister, although she's earned one black spot from the whips for voting in favour of an in-out referendum on the EU. Her City career included 10 years in BZW (the investment bank subsidiary of Barclays created out of acquisitions in the wake of the Big Bang financial deregulation in the 1980s) and Barclays, and rose to become Financial Institutions Director. In 1995, she worked with the governor of the Bank of England, Eddie George, over the weekend that Barings collapsed. A rare combination of detailed expertise and a sure touch with the media.

Similarly, watch Jesse Norman: a cerebral Tory new boy, who has successfully campaigned to persuade companies involved in the Private Finance Initiative (PFI) to volunteer cuts in their profits, saving a billion for the taxpayer. Another alumnus of BZW. Less likely to engage in performance art than some of his colleagues on the committee. Mark Garnier is another Conservative committee member with an extensive City CV, encompassing Edmond de Rothschild Securities, and Bear Sterns, among others.

John Thurso: the committee's sole Lib Dem, a smart, saturnine Scottish laird, with serious business experience - he sat on the Treasury Committee during the investigations into the credit crunch. The Lib Dem internal joke is that many MPs have a big estate in their constituency - John Thurso has a constituency in his big estate. Stewart Hosie is the SNP's Treasury and Economics spokesman in Westminster.

Unknown quantities: Labour's Andy Love - who tends to be a low key figure in public sessions of the committee - and Teresa Pearce, also Labour, is the newest member of the committee and a former tax investigator at PriceWaterhouseCooper.