LONDON (Reuters) - Former Barclays boss Jes Staley will on Monday mount a high-profile appeal against his proposed ban from Britain's finance industry, which will once again highlight his relationship with disgraced financier Jeffrey Epstein.

Staley - also a former executive at JPMorgan, where Epstein was once a major private banking client - has been battling to clear his name since 2021, when he left Barclays under a cloud caused by his past association with Epstein.

Britain's Financial Conduct Authority (FCA) said in 2023 that it intended to ban Staley from senior roles over a letter sent by Barclays to the financial watchdog in 2019, two months after Epstein died in jail awaiting trial for sex trafficking.

The FCA alleges Staley approved the letter which contained two misleading statements about how close he was to Epstein and that his last contact with the financier was "well before he joined Barclays in 2015".

Staley denies the allegations. In court filings, Staley says the FCA's decision - which also includes a 1.8 million-pound ($2.3 million) fine - was made unfairly as it did not give him or Barclays an opportunity to explain how the key letter was approved.

His three-week appeal will hear evidence from high-profile figures from the world of finance, including Bank of England Governor Andrew Bailey, who was FCA chief executive between 2016 and 2020, and Barclays Chair Nigel Higgins.

It will also feature references to some of Epstein's other well-known associates, such as Britain's Prince Andrew and Peter Mandleson, now British ambassador in Washington.

Staley will be cross-examined over the course of four days from March 11 while JPMorgan, which in 2023 settled with Staley in the U.S. Virgin Islands, is likely to be represented.

The bank's lawyers said at a hearing in January that it wished to attend as some of Staley's evidence "relates to JPMorgan individuals and employees".

The FCA's case will rely on around 1,200 emails between Staley and Epstein, in which Staley described their friendship as "profound" and referred to Epstein as "family".

The watchdog is also using emails it received from Epstein's estate, which it says show Staley remained in contact with Epstein until at least 2017 through Staley's daughter.

But Staley's lawyers say in court filings that those communications were all initiated by Epstein and had not led to further contact between the men.

($1 = 0.7942 pounds)