A trade union branch representing workers across Devon and Cornwall has called for South West Water to be brought into public ownership amid growing concerns over sewage pollution, water quality and rising customer bills.

Members of Unite SW008, the largest Unite branch in Devon and Cornwall, passed a motion backing the renationalisation of the region's water supplier.

The branch believes it is the first local union branch in the South West to make a formal call for South West Water to return to public ownership.

The motion comes as water companies across England face increasing scrutiny over sewage discharges into rivers and coastal waters, as well as criticism over executive pay, shareholder dividends and infrastructure investment.

South West Water, which serves around 1.8 million customers across Devon, Cornwall and parts of Dorset and Somerset, has faced repeated criticism from campaigners and local politicians over pollution incidents and wastewater releases.

The union's intervention follows a series of motions passed by councils in Cornwall expressing no confidence in the company as part of the Dowr Glan ("Clean Water") campaign, which has called for greater accountability and improvements to water quality.

Unite nationally supports public ownership of key utilities, including water services. However, supporters of the motion said the decision by the Devon and Cornwall branch reflected growing local frustration with the current system.

Andy Cooper, treasurer of Unite SW008, said water should be treated as an essential public service rather than a commercial enterprise.

"People in Devon and Cornwall are paying some of the highest bills in the country while seeing sewage pumped into rivers and seas," he said.

"Public ownership is not an abstract idea here; it is a practical response to a system that is failing communities."

The debate over water ownership has intensified in recent years as public trust in the industry has declined.

Polling has repeatedly shown strong support for public ownership of water companies, while environmental groups have argued that the current regulatory system has failed to prevent pollution incidents.

Water companies have maintained that significant investment is being made to improve infrastructure and reduce storm overflow discharges, arguing that many of the problems stem from ageing networks and increasing pressure from population growth and extreme weather.

Campaigners involved in the Dowr Glan movement said water pollution had become a defining issue in Cornwall, particularly for communities dependent on clean beaches, rivers and coastal waters.

Penryn town councillor Mael Gaeric, who is also a member of Unite, said concerns about sewage spills were driving demands for change.

"It’s time to end this charade," he said. "We see massive sewage spills every time it rains and continuing discharges even when it's dry."

The union branch plans to discuss potential routes to public ownership at its upcoming Unite on the Hill festival at Maker Heights in Cornwall later this month.

The motion will also be circulated to MPs, councillors and regional stakeholders, with campaigners calling for legislation that would allow water services in England to return to public ownership.