A VAN driver from Pulborough was seriously injured in a crash near Ashurst on Sunday morning.
Police say the crash happened at 8.25am on the A264 between East Grinstead and Tunbridge Wells.
The vehicles involved were a grey Toyota Auris hatchback and a white Peugeot 206 van, which had been travelling in opposite directions.
The van driver, whom police describe as 40 years old, was taken to King’s College Hospital in London.
On Monday, police said he had suffered serious fractures and internal injuries, and was in a critical but stable condition.
The Toyota driver - described by police as a 23 year old man from Tunbridge Wells - was slightly injured.
He has been arrested on suspicion of dangerous driving and driving with excess alcohol, and has been released on police bail until April 28.
A passenger in the Toyota, aged 24 and from Sandhurst in Kent, was unharmed.
Sussex Police are asking anyone who witnessed the crash to contact them on 101, quoting Operation Sidmouth.