Police are appealing for witnesses following a serious collision on the A26 between Rose Hill and Little Horsted near Uckfield.
Officers were called to the junction with Bradfords Lane at about 4.15pm on Sunday, August 7, to a collision involving a car and a motorcycle.
The rider, a 22-year-old man, was taken to the Royal Sussex County Hospital with serious injuries and remains in a life-threatening condition.
Officers are appealing for witnesses or anyone with relevant footage to come forward.
The collision involved a black Audi Q2, and an orange KTM 125 motorcycle.
Anyone who saw or has footage of the vehicles in the area before the incident is also asked to contact us.
Information can be reported online, on 101, or email: collision.appeal@sussex.police.uk and quote Operation Rowhill.