Up to 60 firefighters have been fighting to save a country pub west of Christchurch.

The Kirwee Tavern, on the road to Darfield, was well ablaze when the alarm was raised just before midnight.

The local fire station is only a few hundred metres away.

A ladder unit had to be used to get water onto flames engulfing the upper floor of the two-storey building near the intersection of State Highway 73 and Courtenay Road.

Eight fire engines, two water tankers, a ladder unit and 60 personnel fought the blaze at the pub, 39km west of Christchurch.

Fire and Emergency shift manager Riwai Grace said crews hadn't left the fire scene until almost noon on Christmas Day.

"They couldn't get into the building because it was too dangerous so they had to fight the fire externally and the last fire crews have only just left the scene now - it's 11.33am."

Grace said at the height of the fire, the ladder unit was used to get water onto flames engulfing the upper floor of the two-storey building.

"It's taken major damage and it'll be left up to the insurance assessors as to what happens to the building. Unfortunately it's not a good picture on Christmas day. Yeah, pretty gutting for the local community."

Thankfully, no-one was injured in the blaze, Graces said.

It was not yet known how it started and didn't appear there was anyone in the building when the fire started, he said.