Planning officers have recommended plans for fracking for shale gas at a site in Lancashire should be approved - but have maintained their opposition to a second scheme.
Lancashire County Council has published reports with recommendations on planning applications from shale company Cuadrilla to develop two new sites between Preston and Blackpool to explore for shale gas by drilling, fracking and testing the flow of gas.
The report recommended that the application for a site at Preston New Road near Little Plumpton be passed, subject to a number of conditions being met, but plans for a similar site at Roseacre Wood should be turned down because of an increase in traffic.
The council's development control committee is due to make decisions on the planning applications next week.
Cuadrilla submitted revised plans after planning officers recommended refusal for both sites in January for different reasons.
Planning officers had previously said the site at Preston New Road should be turned down because of concerns over noise impacts which would ''unnecessarily and unacceptably'' affect neighbouring properties.
But now they have recommended its approval if a number of conditions are met, including controlling time limits, hours of working, control of noise and highway matters.
At the Roseacre Wood site, planning officers maintained their stance that there would be an increase in traffic, particularly heavy goods vehicles, which would result in ''an unacceptable impact'' on rural roads and reduce road safety.
The Government is pushing for the development of a shale gas industry in the UK, claiming it would create jobs and growth, reduce energy prices and cut the country's reliance on gas imports.
Opponents have raised fears that the process causes earthquakes, can pollute water supplies, and could lead to inappropriate development in the countryside and damage house prices.
Hydraulic fracturing - or fracking - involves pumping water, chemicals and sand at high pressure underground to fracture shale rock and release the gas trapped in it.
Drilling at up to four exploration wells on both sites would commence if councillors approve the applications.
Cuadrilla welcomed the recommendation that the Preston New Road proposals should go ahead, but said they were "disappointed" that the planning officers had not recommended that the Roseacre Wood site should also be given the green light.
But environmental campaigners said there were unacceptable and potentially damaging impacts of fracking and called on councillors to turn down both schemes.
In its report on Preston New Road, planners said predicted noise levels would fall below national guidance after Cuadrilla put in new measures including "limiting the height of the drilling rig and enclosing the site and particular pieces of plant and equipment".
The report concluded: "It is therefore concluded that the proposal complies with national guidance regarding the exploration and appraisal for shale gas.
"Whilst there would be some negative impacts, most particularly for those living in closest proximity to the site, they would be for a temporary period and could be made acceptable by planning condition."
And it said: "The proposal would bring benefits by establishing the presence and viability of exploiting an indigenous resource which could contribute to the national energy needs of maintaining a diverse energy supply and would bring some local benefits to the area in terms of employment and contributions to the local economy."
Despite Cuadrilla submitting more information on the Roseacre Wood scheme, planning officers still concluded it "would generate an increase in traffic, particularly HGV movements, that would result in an unacceptable impact on the rural highway network and on existing road users, particularly vulnerable road users and a reduction in overall highway safety that would be severe."
Greenpeace UK energy and climate campaigner Daisy Sands said: "Planning officials have shown there are strong grounds to reject fracking at one of Cuadrilla's two sites. But councillors have even more compelling reasons to deny it at both.
"There's just too much research pointing to the potentially damaging impacts on water supply and air quality, as well as strong public opposition, for fracking to be allowed in the UK again."
Furqan Naeem, from Friends of the Earth, said: "The council must now listen to the tens of thousands of people who have objected to fracking at both sites, and the strong evidence put before them, and reject both of Cuadrilla's proposals to frack.
"Rejecting Cuadrilla's plans is the only way to stop Lancashire's communities and environment being made the UK's guinea pig for risky and polluting fracking."
A Cuadrilla spokesman said officers had recommended refusal at Preston New Road in January only on grounds of night-time noise, and the company had submitted additional information on measures "to further bring down noise levels well below limits set out in government guidance".
For Roseacre Wood, Cuadrilla supplied additional information regarding traffic routes after planning officers recommended in January the scheme be turned down over traffic impacts.
"Whilst we remain confident that our original proposed route was adequate, the alternative route suggested also met with all necessary guidelines in our view.
"We are disappointed that officers do not support this in their negative recommendation today; however, we are pleased to note that, as with Preston New Road, they are satisfied with all other aspects of the Roseacre Wood planning applications," he said.
Green Party leader Natalie Bennett said she would be joining anti-fracking protests outside the council meeting, and called for the councillors to consider the strength of opposition to fracking in the surriounding communities and around the country.
By the end of May, 18,022 representations objecting to the Preston New Road proposal had been received. Some 217 letters have been received in support of the proposal, including a letter from the North West Energy Task Force signed by 120 business leaders.