Dramatic images show the blaze ripping through the workshop on Goldsmith Avenue where crews from Cosham and Southsea, Fareham, Portchester and Eastleigh have been called after the fire has ripped through the garage and spread to neighbour properties
Concerns have been raised after Gas Bottles used for Welding were caught in the blaze.
Ten pumps are currently at the scene and further resources have been requested after it is understood that crews are battling to stop the blaze from spreading further.
Orchard Road in Southsea has also been closed and resident have been evacuated from their homes.
The fire has spread through the rest of the building and into the roof.
The workshop has been completely destroyed, along with several cars that were kept inside.
Officers are set to carry out an investigation to determine the cause.