Vector says repairing the broken Maui pipeline is extremely dangerous work, as it could explode from residual gas.
Thousands of companies have been without a mains gas supply since a break was found in the pipe in Taranaki on Sunday.
Chief executive Simon McKenzie says work went through the night again in difficult conditions in north Taranaki.
A team is trying to weld a piece of pipe to replace the broken section.
Mr McKenzie says it is extremely dangerous work as the pipeline could have residual gas, which could explode.
It is also challenging for the repair crew who are also having to work down a hole in very muddy conditions.
Vector hopes full gas supply will be available on Sunday night or Monday morning.