West Sussex Fire and Rescue Service said crews were first called to the blaze at 5.24pm today, April 22.
And six fire engines – one from Shoreham, one from Henfield, one from Burgess Hill, two from Brighton and one from Hove – have been sent to tackle the blaze at The Dyke Golf Club, off Devil’s Dyke Road in Poynings.
The fire, which is not thought to involve any buildings, is also being fought using a command unit from Haywards Heath, two off road vehicles from Crawley and Horsham and a water carrier from Burgess Hill.
A spokesman confirmed the technical rescue unit is at the scene and a drone is surveying the fire.
Shortly after 6.30pm the fire service confirmed the blaze was around 200 square metres – around three quarters the size of a tennis court.
The spokesman added that a second water carrier from Petworth and another off road vehicle from Midhurst were being sent to the scene.
In an update at 7pm, he said: “Crews remain on scene and are bringing the fire involving grass and gorseland under control.
“We would urge people to continue to keep their doors and windows closed this evening due to the amount of smoke in the area.”
At 8.25pm, the spokesman added: “Our crews are making steady progress and continuing to dampen down hotspots.
“Relief crews are being brought in.”
At 9.45pm the spokesman: ”The incident has been scaled back and we now just have one pump in attendance, carrying out a watching brief into the night.”