The Global Champions Tour aims to return to London in 2017, after confirming that London 2016 is off the calendar.
However, where it will be staged remains a mystery.
A GCT spokesman could only say they were aiming to secure a “special central venue,” while Royal Parks, who administer London’s most famous open spaces, also refused to comment on discussions. Royal Parks recently revealed that Horseguards Parade was only a one-year arrangement for GCT 2014.
Earlier this year, GCT revealed that just one weekend remained available for the two cities not yet allocated. GCT eventually chose Paris, where free admission for 4,000 spectators daily has been announced.
The high cost of ticket at the UK GCTs has been criticised. The London GCT has also been at three venues in three years.
A GCT spokesman said: “We currently work on the basis of a maximum 15 events for our season.
“We recognise that Britain is a strong horse country — our goal is to return a central venue that is as accessible as possible to as many fans as possible. Our priority is also to achieve a multi-year agreement so we have a consistent location.
“We are in discussions about the venue for 2017 and beyond, and will release more information when it becomes available. Our events take place in very special destinations, with the aim of taking the sport to exciting new levels.
“We do try to offer free admission where possible; however it very much depends on location and who we are in collaboration with.”
The Paris event will be held at the historic park La Plaine de Jeux de Bagatelle in the Bois de Boulogne on the banks of the River Seine.
The new destination of Mexico City will run from 14-16 April at Chapultepec Park.