Race organisers ACU Events have issued a red flag procedure following the incident in last night’s practice.

Steve Mercer is critical but stable in hospital in Liverpool after his machine was involved in a collision with a course car at Ballacrye, near Ballaugh.

The course car was on its way to the accident which claimed the life of Manx TT star Dan Kneen.

Gary Thompson MBE, Clerk of the Course, has confirmed that following the incident, a strict red flag procedure will now take place with immediate effect.

A red flag instruction will apply to the entire TT Mountain Course irrespective of where that incident has occurred.

There will be no movement on the TT Mountain Course by any rider until the incident has been cleared, regardless of how long that incident may take to clear.

The riders will only be permitted to move in course direction under the control of travelling marshals at the front and rear.Editor's note: We have removed comments from this story.