Greens candidate Lidia Thorpe and Labor candidate Clare Burns cross paths at Thornbury primary school on Saturday. Credit:Darrian Traynor The Greens will use their win in Northcote as a springboard to try to wrest two more inner-city seats from Labor next year, Brunswick and Richmond, and force the Andrews government into a progressive coalition. There was dismay at the byelection result among some Andrews government MPs and a sense that Northcote voters had failed to give the party credit for recent progressive policy announcements such as rental reforms and legalising a safe injecting room. One minister said the poor result was a sign Labor should shift its focus to winning the outer suburbs and marginal Liberal-held regional seats such as Ripon and South Barwon. "Outer suburbs – what are they concerned about? Getting home at night, they're concerned about jobs, they're concerned about good schools and we do have a good track record there," the MP said.

The MP said at voting booths on Saturday they witnessed "wealthy people turning up in a nice Subaru or Volvo who were going in to vote Green". But MPs also argued Labor could hold onto the seats of Brunswick and Richmond in a general election next November and retain government in its own right. "You can't discount incumbency," one inner-city Labor MP said. Northcote voters snubbed the Andrews government's appeals to vote for its candidate Clare Burns, backed by a string of housing policy announcements targeted at renters and first-home buyers, as well as multimillion-dollar investments in local state schools. The government suffered a 12 per cent swing and lost the seat for the first time in 90 years.

Labor held Northcote with a six per cent margin before the death of sitting MP Fiona Richardson in August triggered the byelection. Another Labor minister said the result was proof that Northcote's demographic had changed and the area was no longer part of the ALP's base, with huge swings against it even in the former heartland suburb of Preston. "If you want to buy a house in Northcote you have to be extremely well-paid," the minister said. "It's attracting a cohort of people who have the capacity to be free and easy in how they allocate their vote because materially they are very well off." Labor holds the balance of power by two seats, but former deputy speaker now crossbencher Don Nardella has agreed to give the government his vote. Jubilant Greens MPs said the party would aim to win five lower house seats after the next general election – Melbourne, Prahran, Northcote, Brunswick and Richmond – and take the balance of power.

"We want to form a progressive government in Victoria and we would be doing everything that we can to ensure progressive ideas and policies are implemented," Victorian Greens leader Samantha Ratnam said. Party strategists believe the Greens' strong level of support in inner Melbourne forced the Andrews government to adopt Greens policies such as banning plastic bags and backflipping on its opposition to a medically supervised injecting room. Melbourne MP Ellen Sandell said the Greens would exert the same pressure to lobby Labor to join it in creating the proposed Great Forest National Park in the central highlands. The Liberal Party did not field a candidate in Northcote and has signalled that it will no longer run in seats where the contest is between Labor and the Greens. "The Liberal Party is no longer a preference machine for the Labor Party in inner city seats," Opposition Leader Matthew Guy said on Sunday.

"We're not there to roll up and get these people elected." A Labor MP conceded the Liberals have indirectly helped Labor fend off the Greens in the inner-city because their voters generally preference the ALP ahead of the Greens. Ged Kearney, the ACTU president who will replace Labor's Jane Garrett as the candidate for Brunswick at next year's election, said Saturday's result did not shake her view that Labor could retain the marginal seat. "We have a good Labor government that is doing great things for the state and I'm proud to be a part of that and I'll be running on that legacy," Ms Kearney said. Loading

Police Minister Lisa Neville, who opened a new 24-hour police station in Mernda on Sunday, said the result did not indicate voters were angry at the Andrews government. "I know one of the messages in Northcote was very much people wanted to support a Labor government and felt they could do that by still voting Green," she said.