A consultation on plans for the UK's biggest solar farm is due to end at midnight.
The Mallard Pass Solar Farm would cover the equivalent of nearly 1,700 football pitches around the Lincolnshire and Rutland border, generating enough energy for thousands of homes.
Opponents say the development would spoil wildlife and take away agricultural land.
The application is due to be considered next spring.
The total number of solar panels were reduced after the first round of consultation but the site would still be eight times bigger than the UK's current largest solar farm, measuring 4.2 miles (6.7km) from end to end.
Residents against the plans set up an action group led by Keith Busfield.
Following Mr Busfield's death, his partner Sue Holloway said they were even more determined to stop the solar farm.
"We are so concerned about this huge, large-scale proposal and we don't feel - particularly with it being a national infrastructure project - we've got much of a voice," she said.
"This consultation is important because it's a statutory part of the process, whereas the previous consultation was voluntary."
Other local people supported the plans and thought the environmental benefits of a solar farm outweighed any negatives.
Adam and Abbie Boylan said it was necessary as an alternative to fossil fuel.
"If you can take a resource from something that's free, I think that's a win," said Mrs Boylan.
Helen Kenworthy said: "It's fantastic. It's got to be done hasn't it?
"Otherwise, where is the energy going to come from?
"I think a lot of people are of the opinion that it's necessary and renewable energy is the way forward.
"But equally, I think a lot of people are hoping that it's going to come from somewhere else other than locally."
A decision on the plans is due to be made by the government in spring next year.
South Kesteven District Council leader Kelham Cooke urged residents to get involved with the consultation at a recent full council meeting.
"I would strongly encourage people to respond by 4 August. There has been a massive community swell against the application," he told the Local Democracy Reporting Service.
"I would like to pay tribute to Sue Holloway and the Mallard Pass Action Group. If you drive around the south of the district, you will see banners and signs in literally every village."
The solar panels would be 11 feet high, and could power 92,000 homes over the next 30 years.
The application is being brought by Windel Energy and Canadian Solar, who say it would generate large amounts of clean energy.
Windel Energy has previously told the BBC: "Mallard Pass will support the urgent need to decarbonise our electricity system, deliver reliable and sustainable low-cost energy, enhance the local environment and be a responsible neighbour."