Western region spokeswoman for lobby group Taxed Out, Nola Dunn, said the leaflet drop was targeted at voters in the west.

"We are hitting every [state] Labor electorate on this side of town," she said.

"Because they're such safe Labor seats in the west, Labor treats the residents badly. People have worked hard all their life for their land, but they'll walk away with nothing if they have to pay this tax."

Melton MP Don Nardella said it was a "scare campaign" that would not help the group's cause. "It's absolutely inappropriate."

Legislation for the tax and the final UGB outline are expected to be presented to State Parliament this year.

The leaflet drop follows meetings in Melton attended by hundreds of residents, a march on State Parliament in June, and a recent half-page advertisement in a daily newspaper calling for the tax to be abolished.

Taxed Out is calling for Planning Minister Justin Madden to release the Charter Keck Cramer report - the land valuation study which formed the basis of the $95,000 per hectare figure.

The independent statutory body responsible for planning the growth areas, the Growth Areas Authority, says 37,000 homes for 90,000 people will be built in Melton over the next 25 years.

Melton Council supports payment of the tax when the land is developed.

State Government spokesman Chris Owner said the GAIC would pay for the new roads and infrastructure needed to support growth.

"In order to get this important piece of policy right, the Government has engaged widely with the community.

"It will consider all submissions, including those wishing to be exempt, before any final decisions are made and introduced to Parliament."