Lancashire County Council will rule on the American firm's £300m plans tomorrow.

Local residents are hoping councillors follow the lead of County Hall planning officers by refusing permission to store gas in hollowed-out salt caverns under the River Wyre at Preesall.

But Canatxx bosses delivered a blow to anyone who thought they would throw their hand in following tomorrow's meeting.

They announced they will not give up the fight during a series of presentations to members of County Hall's development control committee ahead of tomorrow's showdown.

Local MPs Joan Humble and Ben Wallace, a representative from Fleetwood Town Council, residents opposing the scheme and a lawyer employed by Canatxx took to the stand for 30 minutes each to argue their case.

Stalmine farmer June Jackson, a long-time opponent of Canatxx, said: "There are so many unknown elements and unknown questions in relation to the brinefield. The salt has not been proven capable of storing gas.

"In October 2007, the Secretary of State agreed with the inspector and refused the application. We believe the reasons are still valid."

Protect Wyre Group (PWG) brought up concerns of gas migration from caverns and the unsuitability of the salt.

Ian Mulroy, chairman of PWG, also showed the committee images of fireballs from an explosion at a gas storage facility in Hutchinson, Kansas, in 2001. He said there were similarities between the Hutchinson salt and that in Preesall.

He said: "The gas seeped and made its way to the surface, causing explosions, fires and fatalities.

"This is dangerous stuff. Canatxx has failed to provide sufficient information to prove without doubt that the Preesall salt is suitable for gas storage. They are in denial."

And Coun Rebecca Murdoch, from Fleetwood Town Council, said: "What would happen if there was an explosion? Fleetwood is a peninsula, it's only got two roads out.

"Where would the 30,000 people go if they had to be evacuated? None of it has been considered in their planning application."

But Patrick Robinson, a planning law specialist in underground storage representing Canatxx, argued there was "a consensus that the UK needs gas storage".

He said: "This contribution of 1.2m tonnes is significant such is the demand we are facing.