He has been hired as the replacement for Sean Worth, who is leaving to set up his own consultancy.
He will formally start at Quiller in the autumn but the date of his departure from Christie’s is yet to be resolved.
His experience as Barclays’ director of corporate affairs between 2008 and 2013 is expected to prove useful to Quiller as it defends its UK public affairs contract with HSBC.
James ran the PR agency Brown Lloyd James, in which he was a partner, between 1997 and 2004. He subsequently became the permanent secretary for government communications before moving to Barclays.
James and Huntsworth chief executive and Conservative peer Lord Chadlington have worked together before, when James was political secretary to the Prime Minister John Major.
Quiller’s clients include the United Arab Emirates, which supplied a large chunk of the money that helped Barclays avoid being forced to take a government bailout in the 2008 banking crash.