By Jonathan Leask, local democracy reporter The government's message is consider amalgamation or be merged, but some Canterbury councils won't be rushing into a decision. The government has given councils an ultimatum to prepare amalgamation plans within three months, or the government will do it. Local Government Minister Simon Watts and RMA Reform Minister Chris Bishop announced on Tuesday a three-month deadline for reorganisation plans to be delivered. "Our message to councils is simple: lead your own reform, or we will do it for you. Either way, change is coming," Bishop said. A Greater Christchurch Super city model has been touted, and supported by Christchurch City Council, but there have been reservations by Waimakariri and Selwyn. Following Tuesday's announcement, Selwyn mayor Lydia Gliddon said she was surprised by the short timeline. "When this was first talked about, the timeframe was closer to two years, so the move to just three months is a significant change," Gliddon said.…