In a dramatic twist of events, two former traders convicted of manipulating benchmark interest rates faced a crushing blow as an English appellate court upheld their convictions, deeming their trials fair.

The Court of Appeal dismissed efforts by Tom Hayes, 44, a former trader with Citigroup and UBS, and Carlo Palombo, a former Barclays banker, to overturn their convictions for allegedly submitting false interest rate submissions during the tumultuous 2008 financial crisis.

Justice David Bean emphasized that binding precedent required submissions to reflect the cheapest or best rate at which banks could borrow, underscoring the gravity of their actions during a critical juncture in financial history.

While a U.S. appellate court approached the matter differently, Justice Bean asserted that the essence of Libor and Euribor codes constituted binding contracts akin to legislation. Permitting jurors to decipher their meaning risked inconsistent verdicts, he cautioned.

"The jury in these cases could not address whether the submissions were, or would be, an honest and genuine assessment without being given an answer to the question, 'An assessment of what?'" Justice Bean elucidated.

Despite the setback, the two men have a narrow window of opportunity, with 14 days to petition for permission to appeal to the U.K. Supreme Court.

Hayes, undeterred, vowed to challenge the ruling, with his lawyer, Karen Todner, affirming the case's significance and advocating for its consideration by the highest echelons of British jurisprudence.

The ruling comes after a riveting three-day hearing where Hayes' legal team contended that the trial judge had deprived him of a fair jury trial. Hayes, previously convicted of conspiring to rig Libor, received an 11-year prison sentence in 2015, while Palombo, found guilty of rigging Euribor, faced a four-year sentence in 2019.

Both rates, Libor and Euribor, held monumental sway, influencing trillions of pounds in financial products.

The convoluted legal saga took a global turn as Hayes' alleged co-conspirators were cleared of similar charges in the U.S., leaving the U.K. as the sole jurisdiction where their actions remained criminal.

In a contentious argument, Hayes contested the judge's characterization of his rates as "false," arguing that the judge's instructions to jurors had prejudiced his case. However, Justice Bean stood firm, asserting that Hayes' attempts to obfuscate his actions and subsequent admissions of dishonesty spoke volumes.

Described as the "ringmaster" of a nefarious plot, Hayes consistently denied wrongdoing, yet the courts upheld his conviction, citing flagrant breaches of regulatory protocol.

The Serious Fraud Office underscored the enduring relevance of the convictions, affirming that accountability knows no bounds, even in the realm of high finance.

As the legal battle rages on, the implications reverberate far beyond the courtroom, casting a shadow over the integrity of global financial markets.