- Eddie Lister was listed as attending property event Mipim as "senior strategic adviser" to the PM.
- However he left the role more than a year ago, Number 10 confirmed.
- Lister told Insider it was an error: "I am going just as me."
Boris Johnson's former senior adviser Eddie Lister was listed as an attendee at one of the world's biggest property events under his old job title.
Lord Udny-Lister was, from August 2019 until February 2021, senior strategic adviser to the prime minister. Before that he worked with Johnson for many years when Johnson was Mayor of London.
Although he does not currently work for the government, Lister appeared on the Mipim delegates list under his former role, two sources confirmed.
Number 10 confirmed Lister no longer worked for Johnson.
Lister told Insider that it was "an error" made during the registration process. He said: "I am not going as anything to do with the government. I am going just as me."
His attendance was also not related to the companies on his register of interests, he said.
Those roles include a non-executive director of office developer Stanhope Holdings and director of property developer Eco World Management and Advisory Service.
He is also director of Eddie Lister Consultants, a firm described on the register as involved in "property development, general business and strategic advice." Its clients include Delancey, HSBC Holdings and metals trader Metdist Enterprises.
Lister said he would travel to the event in Cannes, France, on Tuesday, but would not be speaking publicly. Lister later said he had asked the organisers to update his details.
Angela Rayner, Labour's deputy leader, told Insider: "This is yet another example of the revolving door culture that is rife within this Tory government. Lord Lister is just the latest of the Prime Minister's cronies to cash in on his personal connections with a nod and a wink from the man at the top, and working people are paying the price.
"Lister has already been forced to apologise for approving a £187 million taxpayer-backed loan for a company that was paying him at the time, and this latest development adds yet more questions for him to answer."
During his two-year stint at Number 10, Udy-Lister also served as chief of staff, riding out the period immediately after the shock exit of Dominic Cummings from Number 10. He was made a member of the House of Lords by Johnson in 2020.
After handing over the chief-of-staff reins to Dan Rosenfeld, Lister briefly served as Johnson's Gulf envoy for two months. He departed the government abruptly in April 2021.
The statement from Downing Street confirming his departure made no mention of the reason for Lister's departure. However, it came shortly after The Times reported that Lister held talks about a six-figure contract with Finsbury Glover Hering, a public relations and lobbying firm, which has two offices in the Middle East.