What is the project?

The factory is a €140m joint venture by Glanbia and Dutch company Royal A-Ware that would produce edam and gouda. It is part of a strategy to diversify the Irish export market in the post-Brexit world.

Around 80 workers would be employed at the plant but it is hoped its construction would create hundreds more jobs. Glanbia pays around €1bn a year to 4,500 farmers across Ireland who supply it with milk.

Who is An Taisce and why are they against this?

An Taisce is the National Trust for Ireland which effectively acts as the State’s environmental and heritage watchdog. It runs programmes like the National Spring Clean; the Irish Business Against Litter; National Litter League; and Green Schools. For this it receives State funding, around €675,000 this year and some €5.4m over the previous 12 years, but also relies on membership fees and donations from the public for its advocacy.

An Taisce lodged a High Court action against An Bord Pleanala’s decision to greenlight the cheese plant because it believes this specific development will add to the “perilous state of Ireland’s carbon and pollution footprint”. The court dismissed An Taisce’s case but last Friday the watchdog announced it was appealing the ruling.

An Taisce’s Natural Environment Officer Dr Elaine McGoff told RTÉ on Tuesday: “This plant would just tip us over the edge and in the face of this environmental crisis, the plant would be installing capacity and encouraging investment by farmers and essentially hardwiring us into an unsustainable future.”

She said the organisation wants to know what the correct standard of environmental assessment is under EU law.

What has been the political reaction to this decision?

Fine Gael and Fianna Fáil TDs, particularly in rural Ireland, are angry, arguing that An Taisce’s decision is delaying much-needed investment and job creation in the southeast and that generally the organisation is stymying development in rural Ireland. OPW Minister Patrick O’Donovan described An Taisce as “serial objectors” in a scathing attack on Limerick 95fm today.

A group of Fine Gael TDs and Senators, known as the “gang of six”, said in a statement at the weekend that An Taisce’s funding and statutory role should be reviewed.

Fianna Fáil’s former agriculture minister Barry Cowen said An Taisce’s latest move highlighted a “shambolic system that curtails/threatens investment/livelihoods in [the] region's dairy sector”.

Significantly, Taoiseach Micheál Martin intervened on Tuesday, calling on An Taisce to effectively end their appeal.

“It’s gone through a very lengthy process already. I would appeal that there would be no further appeals against this project now, given the fact that the courts have ruled very clearly in relation to it and very many jobs depend on it,” he told the Dáil.

Meanwhile, Agriculture Minister Charlie McConalogue said he echoed and supported the Taoiseach, while noting the Government cannot interfere in the planning process.

"Now appears to be the right time to draw a line under the situation and move on – further disruption and conflict will not serve our sector or, indeed, our country well as it could impact on our reputation as being an open and FDI-friendly country," he said.

He urged Glanbia and An Taisce to "engage meaningfully to find common ground for the good of our farmers, our economy and our environment".

How has this gone down with the Green Party?

Not well. The party’s planning spokesperson Steven Matthews expressed disappointment with Mr Martin’s comments. Without directly naming him, Children’s Minister Roderic O’Gorman rebuked the Taoiseach on Morning Ireland. “It’s best for these legal processes to play out, and I would generally say politicians should leave it to play out,” he said.

Through a spokesperson, Green Party leader Eamon Ryan appeared to more or less agree with this, saying it was a matter for An Taisce.

“An Taisce plays an important role in the protection of our shared heritage. It has been a consistent and independent voice for the environment for decades and contributed to many initiatives including our Green Schools programme,” the spokesperson said.

“Its role in the planning process is provided for in law and it has done an important job in ensuring adherence to environmental legislation. Any individual issue or case is a matter for An Taisce and the planning and legal processes.”

An Taisce itself has also criticised the Taoiseach’s intervention with Dr McGoff, describing it as a “highly unusual” move, and adding: “We would ask that the politicians to let us do our job.”

What is Leo Varadkar saying?

Through a spokesman, the Tánaiste has said he backs the project, but significantly he has not joined the Taoiseach in calling for the appeal to be dropped.

Instead, Mr Varadkar believes any appeal should be expedited and the taxpayer should not foot the bill for legal costs.

“The Tánaiste supports the Glanbia/Royal A-ware development and has met the company. It will generate employment in the south-east and income for dairy farmers all across the south,” Mr Varadkar’s spokesman said.

“He agrees with the decision of An Bord Pleanála to grant planning permission and the judgment of the High Court to uphold that decision. He has shared his views with other ministers.

“While An Taisce has the right to appeal the decision, it is up to the court to decide whether there are grounds for an appeal. If there is an appeal, it should be heard quickly as further delays could result in this investment being lost to Ireland. The taxpayer should bear none of the cost of these legal actions if they are unsuccessful and should be borne by An Taisce.”

While An Taisce has not yet said how much has been spent on legal actions, Dr McGoff told RTÉ its advocacy unit is funded through membership fees and donations.

Where is all this heading?

An Taisce is likely to press ahead with its case despite the call from the Taoiseach. That is likely to continue to infuriate TDs in the two large coalition parties and inflame underlying tensions with the Greens who are fundamentally at one with An Taisce on environmental matters.

This row also underscores the extent to which the rock of Ireland’s ambitious climate action targets will increasingly meet the immovable object of the need for economic growth and job creation.

Some argue the two can not only go hand-in-hand but must do so in order to save the planet. However, that view does not resolve the immediate political row that has exposed the deep schism on these matters that exists between many TDs in Fine Gael and Fianna Fáil on one side and their counterparts in the Greens on the others.