[4] He was counsel to the Leveson Inquiry into phone-hacking and media ethics, when he came to public attention due to televising and other reporting.

On 4 June 2013, he was appointed a High Court judge,[5] receiving the customary knighthood in the 2013 Special Honours,[6] and was assigned to the Queen's Bench Division.

[2] In April 2019 Jay was the judge in the fraud trial of four former Barclays bankers (Varley and others) over the bank's Middle Easter fundraising during the financial crisis of 2008.

After months of hearings in the Crown Court at Southwark, Jay made a terminating ruling, discharging the jury.

As well as levelling this mocking criticism at his legal writing, the Court of Appeal allowed the appeal on every ground raised, including the ground that Jay had been so overbearing, rude, and bullying to the claimant (whose first language was not English but Polish, and who was acting without legal help), that the trial had been unfair.