More than £60,000 has been raised towards the cost of pursuing a judicial review into the decision to approve controversial plans to expand the runway at Southampton Airport.
Campaigners said to have received donations from more than 400 people and said to be well on their way to achieving their £100,000 target.
It comes as plans to expand the runway by 164 metres were approved by Eastleigh Borough Council in April this year following hours of debate.
Airport bosses stressed that 4,800 people previously wrote in support of the plans.
But last month campaigners formally submitted an application to the High Court requesting for a judicial review.
The borough council previously said to be confident that its decision-making process was sound.
But campaigners called for the decision to undergo "independent scrutiny" and launched a fundraising campaign to fund the legal challenge.
On Tuesday Airport Expansion Opposition Southampton (AXO) confirmed that the consortium fighting the proposed runway extension has raised more than £60,000 towards the cost of pursuing a judicial review.
GOESA, which was set up by opponents of the plans, has briefed the law firm Leigh Day and will be represented by David Wolfe QC, the same team behind the recent attempt to have the Stonehenge Tunnel declared illegal.
John Lauwerys, from GOESA said, "We have had a really enthusiastic response from the public, especially residents of Southampton, Eastleigh and Winchester who will be most affected by the expansion.
"We believe we have a very strong case, because Eastleigh's decision was flawed both in the way it was taken and the reasons for doing so."
He accused airport bosses to have "failed to acknowledge" the environmental impact of increasing passenger numbers and the impact of noise on local residents.
Steve Szalay, Operations Director at Southampton Airport, said the runway extension will "protect and enable" 2,500 jobs and will deliver "significant economic and employment opportunities".
He added: "We are hugely disappointed by their decision to bring legal action, particularly given that nearly 4,800 local people wrote to express their support for the plans.
"Unfortunately, this legal challenge will delay the creation of much-needed jobs."
Councillor Keith House, leader of Eastleigh Borough Council, said: "Opponents of the airport have every right to progress their objections by a legal challenge.
"The council will be supporting its decision to get the airport back up and running and viable for the future."