A Hampshire city trader accused of rigging Libor interest rates has told a jury he was "chancing his arm" but insisted his bosses knew what he was doing.

Tom Hayes, 35, is accused of masterminding a plot with others to manipulate the rate which affected trillions of dollars worth of financial deals.

But he told jurors at his trial today that he was "confused" by the allegations and that his bosses at the bank Citigroup knew about his activities.

Hayes denies eight counts of conspiracy to defraud from 2006 to 2010, when he worked for Swiss bank UBS and America's Citigroup.

Neil Hawes QC, defending, asked him: "Do you accept that you have acted dishonestly?"

"No, I don't accept that," Hayes said.

Mr Hawes asked: "Do you accept you have entered into an agreement with all of the individuals on the indictment?"

"No, some of them I didn't even know," Hayes responded.

He was questioned about an email he sent to his line manager Chris Cecere at Citigroup in August 2010.

"I want to express my concern about the recent meeting with various lawyers, internal and external," Hayes wrote.

"I have spent numerous hours having discussions about the procedure of setting Libor.

"As you are aware, until this week there has been no internal rule or policy surrounding this practice.

"Therefore I'm not really sure why I am repeatedly being dragged off the desk to discuss this.

"During the various meetings with the lawyers I feel as if I am being accused of doing something wrong.

"I am not sure what exactly I am being accused of and the lawyers do not seem to know or perhaps are not communicating it to me.

"The reasons for me being called to the long and aggressively conducted meetings has not been made clear to me."

Hayes, of Fleet, Hampshire, told the jury at Southwark Crown Court he was "annoyed" about being taken away from the desk and said it was "inconvenient".

He claimed he had no idea what he was being accused of.

"There was never any specific thing or rule or policy," he added.

"The questions were geared towards Libor submissions, my communications with those who gave Libor submissions, but only at Citi, not any communications with third parties."

Mr Hawes asked: "Did you think you had done anything wrong?"

"No, to be honest I was very confused about the whole thing," Hayes replied.

"I spoke to the CEO in his office and even spoke to him on the phone while I was on my stag do in Ireland.

"I said 'what's this all about' and they said it's nothing to worry about.

"I said 'is it bad, am I going to lose my job' and Chris (Cecere) said no."

He went on: "It wasn't made clear to me by the lawyers and even when I asked what rule have I broken it wasn't made clear to me."

He added that the "requests" he made to others concerning the Libor rate, which the Crown alleges were part of a plot to manipulate the rate, were "more of a chancing my arm thing".

"Was what you did clandestine?" Mr Hawes asked.

"No, it was very consistent," Hayes said.

"Everything I did was in complete transparency with my line managers and direct managers.

"There was never anything I did that my managers were not aware of."

Hayes worked for Royal Bank of Scotland and Royal Bank of Canada before joining UBS in 2006 as a trader in Tokyo.

He joined Citi in 2009 and continued working in Tokyo but was sacked after his methods were reported to senior management.

He returned to the UK where he was arrested in December 2012 by the Serious Fraud Office.

Prosecutor Mukul Chawla QC has previously told the court that Hayes allegedly admitted his guilt to investigators and offered to give evidence about others allegedly involved in the scam.

The court has also heard that Hayes has been diagnosed with mild Asperger's syndrome.

Mr Chawla said Libor rates were "rigged to his financial advantage and therefore inevitably to the financial disadvantage of those with whom he was trading".

Hayes was a trader in yen Libor derivatives, effectively betting on movements of the daily rate at which banks are able to borrow from each other.

The case centres on the allegation that he was seeking to rig the submissions made by the panel banks which are used to calculate that rate.

Hayes said he thought there was "no downside" to making Libor rate requests.

He continued: "I was hungry to do the best job I could do. Hungry because of the performance metric and hungry because of the way I was being judged. I was absolutely hungry to do a good job."

Hayes said he was "petrified" when he was arrested in America after being told he would face allegations of fraud in the UK.

"I was facing three counts, each had either 20 or 30 year sentences. Technically I could face a count for each email.

"I had no support network in the States, didn't have my wife or one-year-old son, didn't have my family.

"I was basically living life then on a 24 hour time horizon - how do I get through it, how do I survive.

"Even the arrest (in America) wasn't enough to stop the extradition process."

He added: "It wasn't a situation I chose to be in, I was like in the Twilight Zone."

Hayes said he was portrayed as "the Jesse James of Libor" in the media.

"It wasn't pleasant for me or pleasant for my family," he continued.

"I was made out to be the Jessie James of Libor, the Bobby Davro of Libor.

"I was being portrayed as the architect and the ringmaster of what was a global financial issue."

Hayes was mocked by his former colleagues who nicknamed him "Tommy Chocolate" and "Rain Man", the court was told.

"I wasn't aware of that at the time but it was because when I went drinking with the brokers I would drink hot chocolate and they would drink pints," he said.

"I didn't know of that nickname, didn't think anyone would be bothered if I drank hot chocolate and they drank beer."

He added that his co-workers at UBS dubbed him "Rain Man" because he was "different".

"They thought I was a little bit strange, I took things very literally," Hayes said.

"They used to laugh at me, I had the same superheroes duvet cover I had since I was eight. I didn't see the point buying a new one when that one was perfectly adequate."

Hayes said he was "surprised" by his diagnosis of Asperger's Syndrome earlier this year.

"I didn't think there was anything wrong with me, maybe there isn't anything wrong with me," he told the jury.

"It does explain certain character traits I have, certain obsessions I have - things I care about, I'm obsessive about.

"Even now I'm obsessed by the markets and I very much miss my old job and my career. It was a big part of my identity."

He added: "It was a love-hate job. It could be the worst job in the world, could make you want to jump off a bridge and make you feel physically sick when you went into work.

"But the success when you got it right. That's like solving that equation, it's like seeing that number pop up on your screen. There's no subjectivity, you make money or lose money - it's so pure."

Hayes insisted: "I wanted to do the best job I could. That's just the way I am, it wouldn't matter if I was cleaning a deep fat fryer or de-boning a chicken. Those jobs went to me because they knew if I did them there would be no bones left and no fat in the fryer."

Mr Hawes asked: "Did you regard yourself as being wealthy?"

"Yes," Hayes replied. But he added that he was "not well paid" compared to some of his colleagues.

He claimed he made a total of 300 million dollars profit for his employer UBS in three years from 2007 to 2009.

But Hayes insisted that his performance was not related to setting the Libor rates.

"It's been a big misconception in the media that my profit and loss came from the Libor moving around," he added.

He told the jury he never had any training about Libor submissions or the role of submitters..

"None of my training encompassed Libor or how the submissions came about."

He added: "Libor was in no way, shape or form regulated."

Mr Hawes said: "You have suggested that at that stage it (requesting Libor rates) was commonplace."

"Yes," Hayes replied.

"That at that stage it was accepted," Mr Hawes added.

Hayes answered: "Yes, it's just the way the market was."

"Did anyone at that stage say we shouldn't be doing this?" Mr Hawes said.

Hayes replied that "no one batted an eyelid".

ends Hayes told the jury that setting favourable rates was not dishonest as long as the figures were "justified".

Mr Hawes asked: "Was it permissible to chose the rate that was most favourable to you and the bank?"

Hayes replied: "There's a reason banks wanted to be on the (Libor) panel. I've heard status being mentioned but no one's bonus is based on status. It was because it allowed them (the banks) to make commercially favourable submissions."

He added: "I don't see how the mere fact that it was chosen on a commercial basis is wrong. That's just the way it worked.

"I don't see the difference as long as the number is justified."

He said his bosses at UBS were "low-balling" the Libor Yen rates. Low-balling is when a bank submits a lower interest rate than the rate they could actually borrow at to make their credit position look better.

Hayes added: "It used to drive me nuts because senior management were low-balling the Yen rate which used to affect me.

"I didn't understand how much trouble UBS was in at that stage."

Hayes told the jury that he saw press articles about Libor rates being low-balled in May 2008 but was only interested because of the potential effect on his trading.

He told the jury the Greek bailout in May 2010 had a huge impact on the financial market.

"I was on holiday at the time and was just on my Blackberry the whole time, I was like a zombie," he added.

"I had really big profit and loss swings."

The trial continues tomorrow.