A father-of-four remains in a serious but stable condition in hospital the day after a minibus crash derailed his wedding and injured six people, including members of his bridal party.

Groom John Barrett, from Cessnock, was critically injured when the Toyota HiAce taxi carrying him and his groomsmen on Wednesday morning veered off Mount View Rd at Mount View, in the NSW Hunter Valley region.

WATCH THE VIDEO ABOVE: Groom injured in horror wedding day crash.

Know the news with the 7NEWS app: Download today

The car rolled several times down an embankment.

All six people in the car — a 73-year-old male driver and five men aged in their 50s — were hurt and had to be taken to John Hunter Hospital in Newcastle.

Barrett suffered limb injuries, and a 60-year-old passenger was also taken to hospital with critical head wounds.

Three people have since been discharged from hospital and three remain in a stable condition, including Barrett.

The crash happened just minutes from the groom’s wedding venue, Bistro Molines, about 10.30am.

Barrett was recently diagnosed with motor neurone disease and has been campaigning to find a cure for the illness.

NSW Ambulance Superintendent Jake Broughton-Rouse said it was “a really difficult scene”, with the vehicle rolling about seven times.

“It took a multi-agency and really co-ordinated response to gain access to the vehicle,” he said.

“It took approximately 45 minutes to cut one of the patients out of the minibus.”

NSW Police district commander Superintendent Steve Laksa said it was “very fortunate that the injuries were not fatal”.

“It definitely could have been worse,” he said.

Police said an official investigation is underway and anyone with information should contact Crime Stoppers on 1800 333 000.