The AELTC had proposed the building of a new show court with a capacity of 8,000 and 38 grass courts on parkland that adjoins the exisiting site of the annual grass-court grand slam.
However the most northerly patch of Wimbledon Park is in the borough of Wandsworth, necessitating the backing of both councils for the plans to go ahead.
And ahead of a planning committee meeting on Tuesday 21 November, planning officers in Wandsworth have advised councillors to refuse the application.
They suggested that the expansion would be “inappropriate” and cause “substantial harm” to an area designated as “Metropolitan Open Land”, and thus afforded the same protections as the green belt.
A “Save Wimbledon Park” petition opposing the plans has so far collected nearly 15,000 signatures.
The All England Club currently has 18 competition grass courts, eight American clay courts, two acrylic courts, and six indoor courts, as well as 22 Aorangi Park courts used as practice areas during the annual Championships.
The expansion would allow Wimbledon to hold its qualifying events on site, as is the case at the three other majors on the calendar.
The Club said in a statement: “We are surprised that planning officers at the London Borough of Wandsworth have recommended refusal of the AELTC Wimbledon Park Project, particularly after the London Borough of Merton resolved to approve the application following extensive analysis and debate both in their officers’ report and at the Planning Committee.
“We regret that Wandsworth’s officers have taken a different view but it is for Councillors on the Planning Applications Committee to make their own considered decision at the meeting on 21 November.
“We firmly believe the AELTC Wimbledon Park Project will deliver substantial social, economic and environmental benefits, including 23 acres of newly accessible green space, alongside hundreds of jobs and tens of millions of pounds in economic benefits for our neighbours in Wandsworth, Merton and across London.”
If the plans are approved by the planning committee next Tuesday, they will then be passed to the Mayor of London, Sadiq Khan.