Cantabrians deserve the right to drive the rebuild so that the future city that is one people feel safe in, that they're proud of, and that is a living legacy, Mr Shearer said.
"You can't rebuild Canterbury from the top floor of the Beehive. Its future must be led by the people."
Before he got into politics, Mr Shearer worked for 20 years in disaster recovery around the world.
He told the meeting that while emergencies always begin with a top-down command structure, there must be a shift over time to community-driven leadership.
"The National Government sees democracy as a barrier to its plans," he said.
"It's taking advantage of a tired, distracted and devastated city to push those plans through. My approach as Prime Minister will be very different.
"Under National, Cera has engulfed the functions of councils. Elections have been cancelled and appointees installed. Labour will put Cantabrians back at the centre of their recovery."
Labour is increasing its commitment to the region, he said, with more regular engagement including public meetings every six weeks and visits from senior MPs to discuss critical issues like jobs, housing, education and transport.