Aqua Park opponents are preparing to march on the Senedd in their latest protest against the controversial water park at Cosmeston Lakes.
Campaigners say they are considering legal action as a "last resort" after plans were given the go ahead by Vale of Glamorgan Council last month, despite environmental concerns.
Demonstrators are expected to gather in Cardiff Bay on Wednesay afternoon.
Nearly 7,000 people have signed an online petiton since March, when the Aqua Park group first announce plans to move its Cardiff Bay site to the eastern lake at Cosmeston, due to concerns over water quality.
A 'silent' protest will also be held at Cosmeston is planned on 5th July, when the inflatable assault course is due to open, creating 40 local jobs.
Protesters say the attraction will endanger wildlife at a site of special specific interest (SSI) and "the lives of those" who use the country park, which was granted nature reserve status in 2013.
Saar Lenaerts, an organiser wth the Save Cosmeston and Vale group said: "We are not against the Aqua Park in principle but its location. There are far more suitable and less dangerous places for it to be situated."
"Swimming has been banned in Cosmeston lakes for years due to its past industrial use as a quarry. We simply cannot understand what has changed to suddenly to make it safe. We truly believe people’s lives will be at risk."
"We also believe the ecological and water tests paid for by the company on the request of Natural Resources Wales were inadequate and the council has rushed the plans through without a proper consultation."
"Some people have accused us of being NIMBYs ('not in my back yard'), of being selfish and not thinking of young people, even maliciousness."
"This is simply untrue. Many of the protestors do not live in on Cosmeston’s doorstep and the views of 7,000 people who have signed a petition against the Aqua Park are being blatantly ignored. The Vale of Glamorgan Council’s responses have been divisive, dismissive, and derogatory."
Earlier this month, the leader of Vale of Glamorgan Council accused opponents of spreading "malicious tripe" and basing their campaign on disinformation.
Cllr Lis Burnett went onto allege that her Facebook post had been shared by campaigners "without permission", despite being posted publicly.
There has no further social media comment from Cllr Burnett since her remarks were posted on June 15th.
Vale of Glamorgan Council insists water testing has been carried out as part of work with other agencies to ensure the lake is safe for Aqua Park visitors.
Last month, a council spokesperson said: "The eastern lake at Cosmeston has previously been used for a variety of activities – including boating, canoeing and paddleboarding – and the Aqua Park will have on-site security to reduce any opportunities for anti-social behaviour – including unauthorised camping, lighting of fires, vandalism, fly-tipping."
The county council is expected to carry out a post-pilot evaluation when it closes in mid-September, before deciding if it will go out to tender for someone to operate an attraction on site for the next season.
Connor James, founder of Aqua Park Cardiff, said last month: "The country park is a fantastic venue for our exciting watersport experience, perfect for supervised adventure and family fun. With an exciting new course of obstacles, we can't wait to welcome visitors to our incredible new home."
"We are also really excited to be playing our part in giving people and families much-needed access to active outdoor experience, in a controlled and supervised environment to help boost their physical and mental well-being."

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