Hello everyone. Bob Diamond's appearance in front of the Treasury Select Committee will begin in just under an hour. My colleague Matt Scuffham sets the scene:

Bob Diamond squares up to critical British MPs on Wednesday, a day after quitting as Barclays' chief executive over the Libor interest rate scandal, potentially dragging the Bank of England, government and rival banks deeper into the affair.

Diamond's testimony to a parliamentary inquiry could prove politically explosive; on Tuesday, Barclays published a 2008 internal memo from him which fellow managers understood to mean that the Bank and government might approve if they manipulated the Libor rate at the height of the banking crisis.

The American banker is scheduled to appear before the cross-party Treasury Select Committee at 2 p.m..

Though his compatriots across the Atlantic will be celebrating a holiday marking their independence from Britain, Diamond said he "looked forward to fulfilling" his appointment with the parliament in London, despite having already resigned.

Barclays' defence tactic of claiming official sanction for manipulating a rate at a time of market crisis drew a sceptical response on Tuesday from the man who was British chancellor at the time. Alistair Darling said he could not imagine the central bank asking Barclays to take such action and said his department would never "suggest wrongdoing like this".

Britain's third-biggest bank was fined nearly half a billion dollars for its part in manipulating a key interest rate, the London Interbank Offered Rate, or Libor, which underpins financial transactions worth an estimated $360 trillion (229.52 trillion pounds).

Diamond is the third senior Barclays official to quit over the affair this week, following fines the bank agreed to pay last week of $453 million to British and U.S. authorities.

Barclays said in its submission that it was "ironic" that there had been such an intense focus on it alone, because the company had been the first to settle with authorities over Libor in the midst of a global investigation of the banking industry.

We want to hear from you too, of course. Join the discussion by sending us your comments and questions throughout the hearing and we’ll try to publish/answer as many of them as we can.

Reuters Breakingviews Editor Hugo Dixon was on BBC Radio 4’s Today programme this morning. Asked for his thoughts on the suggestion that Barclays had been encouraged to rig the borrowing rate by the Bank of England, Hugo said:

“There are really two different phases of the rigging, there was the sort of rigging that was happening in the good days in the boom times where traders, reasonably junior people in the bank were manipulating the rate in order to boost their profits … as far as we know that was fairly low down in the organisation.

“The rigging, or the false submissions, that took place in and around the crisis were because Barclays was concerned that it would seem it was an outlier by having higher rates, it was having to pay more to get money than other banks and therefore the market would focus on it and say ‘My God that is a really troubled bank’. So that’s the second phase and it’s a very different phase. And that phase, as we now know, involved Bob Diamond, and it also involved in a way that’s not still clear, this rather odd telephone conversation between Bob Diamond and Paul Tucker.”

Host John Humphrys then asked Hugo what he took from that phone call. Was Bob Diamond being leaned on by the BoE to do what he did?

Hugo said: “If this is an accurate representation of the conversation … and as you said it’s only one side of the conversation … it’s difficult to conclude that the Bank of England in the form of Paul Tucker wasn’t hinting that Barclays could lower its rate … You don’t always have to be higher was what the message essentially was.”

We'll also have a live stream of Diamond's grilling by MPs right here on this page.

Would Barclays have secured funds from Middle East investors, avoided nationalisation and protected its bosses’ bonuses if it hadn't lowered Libor submissions? Reuters Breakingviews Editor Hugo Dixon ponders this very question in this piece.

I'd say I'm watching for three key things in this grilling. Will Diamond try shifting the blame to the Bank of England or the general City culture (as in every major bank was doing it), will he personally apologise, and will he volunteer to surrender his golden parachute? It's not often you get £20m+ for resigning is such circumstances...

Sky reporting Barclays DOES have recording of Tucker-Diamond call. One easy way to settle this spat, fellas. Release the tape.

Is the real concern for Barclays that it chose to "settle" first, hence all of the attention is on them. Would Diamond have left his post if all of the banks involved had been outed at the same time?

RT @ChrisGiles_: Interesting irrelevant fact. Paul Tucker will be in the MPC meeting for most of BD's testimony. Expect many notes to be ...

Mr Andrew Tyrie (Chairman) Conservative
Michael Fallon Conservative Mark Garnier Conservative
Stewart Hosie Scottish National Party
Andrea Leadsom Conservative
Rt Hon Pat McFadden Labour
Mr Andy Love Labour Co-Operative
John Mann Labour
Mr George Mudie Labour
Jesse Norman Conservative
Teresa Pearce Labour
Mr David Ruffley Conservative
John Thurso Liberal Democrat

Paul Tucker keen to appear before the Treasury Committee to put his own case forward.

This story is not just about Libor. That was a tipping point for other concerns and discontent around pay, performance & feeling of distrust

@DGWilkinson Looks like it's running a few minutes late. Shouldn't be long now though.

Hi there ! just heard Tucker wants to appear too

What an entrance!

Thirsty Bob?