ABC 1's Four Corners program has been told property developers now factor in large donations to NSW politicians as part of the cost of doing business in the state.

Developer Hardie Holdings has admitted to paying almost $500,000 in seven years to gain access to state ministers and lobbying the NSW Government to rezone a large area of land in the Hunter Valley for housing.

NSW Planning Minister Frank Sartor stepped in to rezone the land in 2006 against the advice from his department but has denied the decision had anything to do with political donations.

The development - a new town called Huntlee that will house about 20,000 people - is one of the largest ones personally approved by Mr Sartor.

Hardie bought the 1,700 hectares of land for an estimated $75 million.

Immediately after Mr Sartor stepped in to rezone half of it for housing, the company sold it to another developer for $185 million, retaining a 25 per cent share of the project and netting an instant profit of more than $100 million.

Hardie Holdings general manager Matt Somers has told Four Corners, which airs tonight at 8:30pm, developers have to pay hundreds of thousands of dollars in donations to gain access to State Government ministers.

"It's part of the business environment at the moment that people pay donations, not for approvals. They don't pay for approvals, they pay to get access..." he said.

"No-one wants to pay them if you don't have to. We happily support good candidates. We've felt we've paid the money to ensure we have access when we required it...

"We've just dealt with it as a factor of business."

Political historian and ALP member Professor Peter Botsman agrees donating money is necessary to get the ear of the NSW Government.

"There's a relationship established around a donation to a political party which brings also a personal phone relationship and a conversation at a critical time - maybe all that is needed," he said.

Professor Botman says corporate fundraising is also the most powerful thing an ALP member can do.

In the late 1990s, a new class of political deal-makers perfected a system of fundraising that made NSW Labor rich.

A few years ago, property developers overtook the unions as the biggest donors to NSW Labor, giving almost $15 million in nine years.

But NSW ALP assistant general secretary Luke Foley has told Four Corners the party's emphasis on fundraising is dangerous.

"If we're simply a brand with a good advertising campaign when an election comes round and nothing else, we only engage in the empty pursuit of power," he said.

"There's a risk that some people may think they can earn brownie points by bringing in the dollars...

"We ought not tolerate a culture where there's even a perception that bringing in the dollars for the party will get you ahead within the ranks of your political party."

-abc.net.au