More celebrities have voiced anger and alarm at plans for a massive pig farm in Co Antrim.
Actors Martin Shaw and Jenny Seagrove warned the development near Mossley in Newtownabbey would be a disaster - and could open the floodgates for such mega-farms across the UK.
The actors spoke out after Queen guitarist Brian May told the Belfast Telegraph this week of his concerns at the "horrific prospect" of the farm.
The farmer behind the pig plant proposal, Derek Hall, insists his blueprint will result in improved conditions for up to 30,000 pigs using state-of-the-art farming methods.
But Ms Seagrove - star of TV dramas The Woman In White and Barbara Taylor Bradford's A Woman Of Substance - said: "The scale of this farm is inconceivable. This isn't really about better animal welfare; it is about getting pigs from birth to slaughter in the most profitable way possible."
And she added: "If we are not careful, these gigantic animal factories will become the norm.
"We have seen what a disaster they have been in the United States. Do we really want to go down the same route? That is why I'm adding my voice to calls to reject the Newtownabbey mega pig farm."
But Mr Hall insisted his plans were nothing like farms in the US. He said his plans were subject to the "most stringent regulations".
Shaw, best known for starring in The Professionals and Judge John Deed, also hit out. He said: "Factory farming is a cancer - and it might be spreading. We have to stop it in its tracks."
He added: "Opposing these proposals for what would be the UK's largest ever pig farm must be a priority for animal lovers and those who care about our environment, wherever you live.
"If these plans go ahead the floodgates will be open to American-style mega farms and the horrors that entails right across Great Britain and Northern Ireland."
Both celebrities are patrons of the campaign organisation Viva! - Vegetarians International Voice for Animals - which is writing to supporters in the province to boost a public petition against the farm.
In a statement it said: "People in Northern Ireland, and the rest of the UK, are rightly outraged that plans for this mega pig farm have seemingly almost snuck in under the radar.
"The proposals for a smaller farm in Foston, Derbyshire, were rejected recently because of environmental concerns. The truth is that factory farms of this size are potential polluters on a massive scale.
"Much is being made of supposedly better animal welfare, but it is impossible to care for farmed animals in any meaningful way on what is essentially an industrial complex masquerading as a farm.
"Profit is the driving factor here and animals and the countryside be damned. If this proposal goes ahead it could spell the beginning for American-style monster farms to spread right across the UK."
The proposal is being considered by Antrim and Newtownabbey Council, which has indicated any final decision could still be some months away.
More than 2,000 people have already sent formal letters of objection to the council, along with a petition that has been signed by more than 185,000 online.
May, one of the world's leading rock guitarists, said he feared the plan could prove cruel and degrading to the animals and put smaller farms out of business.
But Mr Hall said: "I totally respect the personal choice that Jenny Seagrove and Martin Shaw have made to become long-term committed vegetarians and patrons of an organisation that campaigns for a vegetarian/vegan world.
"It is therefore no surprise they are objecting to my proposal, as I imagine they would object in principle to any farm that isn't organic and/or free-range.
"However, it is always better to have an opinion when you have the full facts, and I wonder if they know where Newtownabbey is or if they even looked at my website nipigfarm.com to find out what it is that I would actually like to do.
"With all the talk about the scale of farming in America, it is little wonder that there are concerns about my proposal. I have visited some of these pig units myself and they are nothing like my plans.
"My family have been farming in Newtownabbey for three generations and we are subject to the most stringent regulations and that is not going to change, nor would we want it to."