A MP has issued a final warning to the chief executive of South West Water following a pollution incident in St Austell.

St Austell and Newquay MP Noah Law states the water and wastewater company’s CEO Susan Davy is on “resignation watch” after the incident at Penewan.

South West Water has confirmed the pollution in St Austell River, which potentially killed thousands of fish on June 19 "occurred as a result of a delivery by a third party to our treatment works" in the Pentewan Valley.

Mr Law has been lobbying the company to take immediate action to upgrade its sewage treatment infrastructure.

He has spent months working with South West Water behind the scenes to discuss and address “multiple issues,” and travelled to its headquarters in Exeter as part of efforts to accelerate improvements to infrastructure.

Mr Law during the meeting called on South West Water to accelerate its plans to spend £700 million on improving infrastructure between 2030-2050, which will reduce the company's pollution by 62%, to no more than 10 incidents per site per year.

But the MP says the company, which recently increased customers’ bills and has been working with the Environment Agency to determine the source of a pollution incident at one of its treatment works in mid Cornwall, has not yet make clear commitments to bring its infrastructure investments forward, or start them within the early part of the first phase of their development programme.

Mr Law said: “Sewage pollution is an absolute priority issue for my constituents who, like me, are very upset by scenes of disgusting pollution across beaches in St Austell and Newquay.”

Mr Law has said the recent environmental disaster at Pentewan, is potentially a “final straw,” although he noted he couldn’t comment further on the specific incident due to it being subject to ongoing investigation by the Environment Agency.

Mr Law said: “Ageing infrastructure is a root cause underlying storm overflow incidents – my constituents’ number one concern – and, while South West Water has made significant commitments between 2030-2050, it would not commit to bringing this forward, or even starting work at the beginning of the cycle.

“It’s effectively a professional way of saying ‘we’ll do it drekkly.’ That’s not good enough for the people I was elected to serve, and I am asking them to bring this work forward.

“I’ve always believed that cooperation is the best way to get things done, and I entered talks with South West Water very much in that spirit but I am slightly disappointed that the chief executive Susan Davy didn't even choose to attend the meeting to discuss this issue of importance and major urgency to my constituents.

“If the company does not agree on that need for urgency then I will call on the chief executive Susan Davy to resign.

“Our beaches are critical to tourism, business and people’s quality of life and I will do whatever it takes to get South West Water to take this issue as seriously as possible.”

Government has already introduced tough new legislation on water companies, with four criminal investigations underway into South West Water.

The Water (Special Measures) is designed to clean up Britain’s seas and rivers and end the payment of undeserved bonuses to water company executives. It could see water bosses across the country jailed for up to five years and water companies fined hundreds of millions of pounds.

“I am committed to doing whatever it takes to clean up our local beaches,” said Mr Law.

South west Water has underlined its 15-year plan to reduce its use of storm overflows.

A spokesperson said: “Regarding investment in infrastructure we run critical national infrastructure and have embarked on our largest ever investment programme across our group, £3.2billion, which spans from Cornwall to Surrey. Eleven of these major projects are in Mr Law’s constituency.

“We are prioritising our investment on what customers have told us are most important to them and to help us deliver on what we promised; to reduce the use of storm overflows, ensuring water resilience and supply, investing in vital infrastructure, supporting customers more than ever and taking a green first approach to our solutions as much as possible.

“The projects in Mr Law’s constituency are part of a much wider 15-year delivery programme to reduce our use of storm overflows which will see us completely redesign our infrastructure network -which if laid out would span the circumference of the world. Work of this scale takes time.

“We recently met with Mr Law to go through our investment plan in his constituency.

“These particular projects will be delivered within the first five years of our 15-year programme. Well ahead of the government’s deadline.”

The projects include Fistral North and South, Yellowsands Sewage Pumping Station, Towan Head Sewage Pumping Station, Readymoney, Fowey Sewage Treatment Works, Town Quay Sewage Pumping Station and Caffa Mill Sewage Pumping Station.

They also include Ready Money Combined Storm Overflow, Par Sands, Luxulyan Sewage Treatment Work, Par No2 Sewage Pumping Station, Charlestown Sewage Pumping Station, Charlestown Remote Sewage Pumping Station, Pentewan (Menagwins) and Menagwins Sewage Treatment Works.

A spokesperson for South West Water said: “They are all included in our AMP8 investment period, set to be delivered by March 2030. Some will be subject to planning permission are being modelled prior to design and delivery, hence the timescale.

“We would also like to extend the invitation to Mr Law to meet with our managing director of Waste Water, at his convenience so that we can help him to understand the work we are doing in his constituency.

“About the management of our business, it’s important to say that we live and work in this region and care deeply about what we all do every single day.

“We are also customers of South West Water. Our 4,000 brilliant colleagues work hard day and night to keep taps running and toilets flushing, we will not stop and we will continue to deliver on our promises.”