Thames Water has added a new clause to some of its financial bonds to ensure investors are paid back immediately if the utility company is nationalised.

In an update recently posted with the Irish Stock Exchange, the supplier’s holding company Kemble Water Finance cites Labour Party plans to nationalise the water industry as a key issue.

It specifically references a party conference speech given by the shadow chancellor, John McDonnell last autumn, in which he said water would be the first industry Labour would bring back into public ownership.

According to the document, any future intervention by a British government in the water markets could affect its ability to meet financial obligations.

The document also states that in the event of nationalisation, investors will be able to demand their money back quickly.

A survey published in March claimed the number of people in favour of nationalising Britain’s water companies has fallen substantially.

The ComRes survey found only two in five (42 per cent) of British adults said they support the nationalisation of water and sewerage services in England, with 37 per cent saying they oppose it.

“The high levels of trust in water companies revealed by this research chimes with the high levels of customer satisfaction that we’ve consistently seen over the years,” said Water UK chief executive, Michael Roberts, speaking last month.

“The country would risk losing the many improvements made to the water and sewerage service over the last three decades if it was brought into government control, and the big plans the industry has to improve the service even further in the future would be thrown into real doubt.”