The move is designed to increase the number of countries participating in equestrian competition at the Olympics.

Previous Games had seen dressage having either three or four members to a team, eventing four or five and show jumping four, and the FEI hope the change will enhance the popularity of the sport worldwide.

"The proposals aim to make the equestrian events more readily understandable and packaged in a more compact format, engaging new fans through enhanced presentation of the sport," the FEI said.

Around 300 delegates are attending the General Assembly in the 2020 Olympic and Paralympic host city, with 76 of the 134 National Federations represented.

The FEI has confirmed 107 members will vote as 31 National Federations will cast their choice by proxy.

German National Federation secretary general Soenke Lauterbach confirmed her nation would not be backing the idea, although two other countries - Denmark and Belarus - have revealed they will vote in favour.

"We understand the desire to get more universality in the Olympic and Paralympic Games, but it has to be balanced with the core principles of our sport, that we have top athletes, top level sport and in line with horse welfare requirements," said Lauterbach.

"We do not feel that with three per team we have the right balance of these three principles and that is why we will vote against tomorrow, but we will accept and work with whatever decision is made."

Another change on the agenda is to scrap the drop score, which previously allowed for a team’s worst score to be discarded.

The alterations to the sport’s Olympic competitions have been initiated by FEI President Ingmar De Vos and tomorrow’s vote represents the end of a lengthy consultation process with various stakeholders.

"We are a sport with 134 National Federations, and it’s correct that not all of them compete at elite level, but the development our sport has seen over the last decades as well as the recommendations of Olympic Agenda 2020 oblige us to focus on an increase in the number of participating nations within the existing quota," De Vos said.

"It is of course our role to get more National Federations to compete at the top level and to offer them an avenue for development.

"The decision is now in the hands of our National Federations and whatever way the vote goes tomorrow, we will make it a success."

Should the changes be approved, the proposals will then go to the IOC Executive Board in February 2017.

The IOC Programme Commission will then make official recommendations to the Board in May.

In July, IOC Executive Board meeting will decide on events and the quota allocation.

The FEI would finalise will finalise the proposal for qualification procedures at next year's General Assembly in Montevideo.