Council leader Cllr Julian Bell, along with seven other council representatives, will attend property fair MIPIM, in Cannes, running from Tuesday to Friday (March 15-18).
The expenses are being funded by 25 sponsors, including Londonewcastle and Benson Elliot, the developers behind the controversial second phase of the Arcadia development, approved on February 24.
The trip has sparked accusations of a conflict of interest, with councillors and Victorian Society questioning the planning committee's ability to have dealt with the application impartially.
But a council spokesperson said the planning committee was a quasi-judicial body - meaning it is separate to the council and deals objectively with evidence to make decisions - made up of elected councillors, none of whom would be attending the conference or work with developers.
They added: "MIPIM is the world’s largest property exhibition and is an efficient way to meet thousands of developers, investors, designers and contractors under one roof so we can highlight the investment opportunities within the borough.
"To strengthen our local economy it is essential that we demonstrate the benefits of investing in Ealing, this will ensure the future success of the borough and help us secure 4,500 new homes and 10,000 new jobs by 2026.
"The council has attended this event for a number of years under both Conservative and Labour control and gets sponsorship from land owners, businesses, housing associations and the University of West London so we are able to go at no cost to local tax payers.
"This sponsorship in no way influences the planning committee’s decisions."
The spokesperson added the sponsorship was not disclosed to the public, or planning committee members, during consultation for the Arcadia development because it had "no bearing" on the decision and was "irrelevant".
Council officials have been attending the fair, which draws boroughs across England, since 2009 as part of the Ealing in London partnership.
Liberal Democrat planning committee member Cllr Jon Ball, who voted against the plans, said he only became aware of the sponsorship when he was in a pub after the meeting.
He added: "I think the whole thing is wrong.
"If the council leader lets it become known he has a view, that is going to have an influence on his group.
"On the day, the majority of the committee who voted for it were Labour."
'Why would we know these things?'
According to City A.M, who claim a pass for the event costs £1,250, Ealing Council sent six representatives in 2015, the third highest of any local government in the country.
Cllr Shital Manro, a planning committee member who voted in favour of the Arcadia development, said: "I was not aware, why would we know these things? We are just the planning committee.
"We turn down things all the time and we approve things all the time."
Conservative member Cllr Alex Stafford, who described the Arcadia development as "Gotham City", said: "I am concerned and confused that the planning committee at the meeting were not made aware of this.
"As a councillor I should have been informed."
Victorian Society, who have asked Secretary of State to "call in" the decision, said they were "losing all confidence in the integrity of the planning process" for developments in Ealing because of the trip.
getwestlondon has approached Londonewcastle and Benson Elliot for comment.