The Victorian government's plans to tax new land buyers on Melbourne's urban fringe is expected to be held up by the Liberals and Greens.

The government has tied the new urban areas to the introduction of a growth areas tax, but The Age reports that the opposition will oppose the new growth areas tax of $95,000 a hectare on new land and is prepared to block the tax even if it means halting the urban expansion.

The tax has been introduced to pay the multibillion-dollar bill for new public transport, schools and hospitals in the growth suburbs, which will be required for the 134,000 new homes, earmarked for the area on the north and west of the city.

Opposition planning spokesman, Matthew Guy, told media: "We have very serious concerns about the current growth areas tax proposal - we offered to negotiate with the government 10 months ago and that has never been taken up."

Greg Barber of the Greens said his party was unlikely to support the movement of the urban growth boundary or the new growth areas tax before '"much further scrutiny''.

Ruth Durack, director of the Urban Design Centre of Western Australia, said taxation was a method employed by governments to direct peoples' decisions. "As an urban design matter - you won't find anyone in the world who doesn't think that sprawl has environmental, social and economic impacts which need to be contained," she said.

Urban designers have also opposed the growth of the city further into the north, claiming that existing suburbs should be better used. Director at MGS Architects Melbourne, Eli Giannini, told Architecture and Design that she was supportive of the 2030 plan, but would encourage infill development first. "I think that we can be a lot denser, we don't necessarily have to go outwards, we can develop areas we have already built on," she said.