By Russell Palmer of RNZ The government has given councils an ultimatum: come up with amalgamation plans within three months or the government will do it for you. Local Government Minister Simon Watts and RMA Reform Minister Chris Bishop announced the move on Tuesday afternoon, giving a three-month deadline for reorganisation plans to be delievered. It followed an announcement in November that groups of city and district mayors - with some government oversight - would be formed to come up with such plans. But the ministers on Tuesday said if councils failed to make use of the new 'Head Start' approach, they would be forced into changes. "Our message to councils is simple: lead your own reform, or we will do it for you. Either way, change is coming," Bishop said. Watts was explicit that proposals should focus on creating larger, more efficient unitary authorities. He said the government was providing councils with "real flexibility".…