Peter Johnson, who admitted deliberately fixing Libor rates in October 2014, was jailed for four years

Four former Barclays bankers who rigged global interest rates have been jailed for a total of more than 17 years.

Peter Johnson, 61, and Jonathan Mathew, 35, who were based in London tweaked the bank's Libor rate in a way that benefited their US co-conspirators, traders Jay Merchant, 45, and Alex Pabon, 38.

The New York traders would tell their London colleagues whether they wanted the Libor rate to move up or down on any given day, 'tipping the odds in their favour', the court heard.

Mathew and Johnson then fixed the rate, which is used to set millions of pounds of financial deals, in a bid increase profits for Barclays while causing potentially enormous losses to others dealing with the bank.

Southwark Crown Court heard that the information submitted in London affected the calculation of what the Libor rate should be for all banks to lend money, not just Barclays.

This rigging took place at a time on financial instability and in the build-up to the 2008 financial market crash.

Prosecutor James Hines QC compared the scheme to bookmakers trying to 'nobble the horse' or telling the jockey 'not to try so hard' ahead of the Grand National.

Merchant, Pabon and Mathew were convicted of conspiracy to defraud after a two month trial. Johnson admitted deliberately fixing Libor rates in October 2014.

Merchant was jailed for six and a half years while Pabon was sentenced to two years and nine months. Johnson and Mathew each received four year jail sentences.

Mr Hines said: 'They were driven by money, their goal was to make more profit on their trading. Honesty and integrity were matters which were entirely expendable. The sums of money involved are enormous - far in excess of the sums we may see in our whole lifetimes.'

Mathew, who worked on the US dollar money markets desk in London, was one of the 'submittors' tasked with submitting the Libor rate each day.

Former Barclays bankers Jonathan Mathew, left, and Alex Pabon, right, arrive for sentencing today

Working with his boss Johnson, Mathew took requests from Merchant and Pabon and changed the Barclays submission in a way that helped the traders rake in more cash.

Mr Hines said: 'The New York traders would tell the submitters which way they wanted the Libor interest rate to go - up or down. The submitters would then do their best to ensure that those requests were carried out.'

Johnson made it clear when questioned that he 'regarded manipulation as dishonest' and that it made his 'blood boil' as it was an 'absolute disgrace'.

During the trial Mathew claimed he was paying 'lip service' to the traders and was simply following his boss's order.

He also said he was bullied by Johnson during Wolf of Wall Street-style antics in the trading room: 'He had a 12-inch bat on his desk and he whacked me on the back of the head and the knuckles.

'It wasn't particularly hard, it was done to humiliate me.'

Mathew, whose father helped him land the job at Barclays, has since re-trained as a chef and was described by his barrister as being 'unlucky' to have become involved in the scheme.

US traders Merchant and Pabon insisted their bosses knew what was going on and it was simply the done thing at Barclays.

Former Barclays trader Jay Merchant was jailed for six and a half years at Southwark Crown Court

Hugh Davies QC, defending Merchant, said: 'He was, in truth, polluting an already polluted environment where the intended approach to the Libor question was simply not being followed.'

Regulator BBA was described as being 'ineffective and commercially driven' as the barrister hinted the conspiracy was wider spread than just those sat in the dock.

'Dozens of people, hundreds even across different banks, could have been in the frame to be prosecuted,' he said.

Mr Davies said Merchant and others were 'picked from a much wider menu of potential candidates' by prosecutors.

Pabon's representative, Tom Allen QC, claimed the now house-husband had not received proper training from Barclays regarding Libor so was unaware of how the rate setting worked.

The traders have been described as 'financially and professionally ruined' and it is unlikely any of them will work in banking again.

Judge Anthony Leonard said rather than a direct financial gain, the bankers acted dishonestly in the hope of 'being promoted to the next level at the bank' by making a profit on their books.

He noted there were sizeable increases in their incomes with Merchant earning more than three times as much in 2007 as he did in 2005.

'I have concluded that the risk of loss can be judged to run into millions of pounds,' he added.

Addressing Merchant, the judge said: 'I judge you, of all the defendants, to bear the greatest responsibility for what happened. It was under your leadership on the desk that requests to the Libor submitters really took off. You abused the position of power, trust and responsibility.'

The judge took into account positive references in Merchant's favour and that he may have to serve his sentence on a different continent to his family.

He told Johnson that he was being held responsible for involving Mathew, adding: 'You abused your position of trust as the Libor submitter who should have put in a rate uninfluenced by requests of the traders.' Johnson, who the judge described as a 'caring, family man', was given a one third discount to his sentence for his guilty plea.

Mathew was handed the same sentence as Johnson despite being his junior as he had continued to contest the charge.

The judge said: 'I have no doubt that you hoped to earn as much as he did in the long term. You were led into this offending albeit voluntarily by Johnson.'

The judge added that Mathew made 'careful calculations' into what the rate should be but that he acted dishonestly over a 'significant period of time'.

Pabon received a shorter sentence due to his shorter period of involvement in the fraud.

The judge said: 'You had the same incentive to improve your position and your income. It follows that both your income and your involvement in the fraud was less than that of your co-defendants.'

Mathew, from Shenfield, Essex, was sentenced to four years behind bars for conspiracy to defraud

Merchant and Pabon, who both live in the US, were jailed for six and a half years and two years and nine months respectively for the same offence.

Johnson, of Tunbridge Wells, admitted the charge and was jailed for four years. He was also ordered to pay back £114,501 and to pay £30,000 costs.

Confiscation proceedings against the other defendants have been adjourned to a later date.

Director of the Serious Fraud Office David Green CB QC said: 'The key issue in this case was dishonesty. By their verdicts the jury demonstrated they were sure that the conduct of three of the defendants, Jonathan Mathew, Jay Merchant and Alex Pabon was dishonest.