Bad weather is interrupting plans to put a seal deep into the main tunnel to the Pike River coal mine.
It had been hoped the drilling of a hole to enable the expanding chemical Rocsil to be pumped in to seal the tunnel could begin on Monday morning.
However, mine manager Steve Ellis says the weather is preventing a helicopter pilot from taking workers up to the site.
He says the hole is likely to take at least a few weeks of drilling time and it not expected to be completed before Christmas.
Mr Ellis says the weather may allow work to begin on Tuesday but otherwise it's looking poor until the weekend.
A seal is already in place at the tunnel's 170 metre mark.
Once the next seal is formed - at the2300 metre mark - the tunnel can be reventilated between the seals and reclaimed.