A satirical blue plaque has appeared in a town accusing its MP of voting to “allow raw sewage to be dumped in a river” – something she says is “absolutely not true.”

The plaque mysteriously appeared on Saturday morning on a wall near Maidstone Bridge, next to the River Medway.

Thousands of visitors walked up and down beside it just as the town’s popular River Festival got underway.

It read: “Helen Grant, 20th October 2021, Voted to allow raw sewage to be dumped in this river. Shameful.”

The date refers to a House of Commons vote when an amendment by the House of Lords to the Environment Bill that would have placed a legal duty on water companies not to pump waste into rivers was voted down.

Mrs Grant, MP for Maidstone and the Weald, was one of 265 MPs who voted to defeat the amendment.

Other Kent MPs who voted against were Laura Trott (Sevenoaks), Tom Tugendhat (Tonbridge and Malling) and Helen Whately (Faversham and Mid Kent).

However, both Greg Clark (Tunbridge Wells) and Tracey Crouch (Chatham and Aylesford) voted for the amendment.

The sign, which appears to have been stuck to the brickwork rather than bolted on, was passed by thousands as the town drew large crowds.

Stewart Jeffery, the Maidstone Green Party leader, was suggested as a potential culprit – something he categorically denied.

However, he did stand for a picture alongside the plaque. Cllr Jeffery said: “There’s been an outpouring of support for the plaque on social media.

“I think that shows the strength of public feeling on the issue. People want the dumping of sewage in our waterways to stop.”

Helen Grant MP has denied the plaque’s claims. She said: “Any suggestion that I voted to legalise or allow more sewage to go into our rivers is absolutely not true.

“I have been very clear that sewage in our rivers is unacceptable. The government is committed to tackling storm overflows and protecting public health and the environment from discharges.

“I voted for targets through the Environment Act 2021 to strengthen the rules on pollution from wastewater and agriculture.

“I have set out below the actions that the government has taken to protect the environment and public health:

“In August 2022, the Storm Overflows Discharge Reduction Plan was launched, setting out stringent targets to protect people and the environment, backed up by up to £56 billion capital investment.

“The Government, the Environment Agency and Ofwat are working to increase the accountability of water companies.”

“This includes increasing monitoring the frequency and duration of discharges, from approximately 7% in 2010 to over 90% now, with 100% by the end of 2023.”

“The Government has also tabled legislation to remove the limit of £250,000 that can be imposed for environmental offences.

“This will mean that penalties can be proportionate to the degree of environmental harm and culpability and can act as a powerful deterrent.

“As set out in the Government’s Plan for Water, future environmental fines from water companies will be re-invested into a new Water Restoration Fund.”

At present, waste can be released from the sewage system into rivers and coastal waters when there is heavy rainfall to ensure the sewage doesn’t back up into people’s homes.

But data suggests the overflow process is used much more frequently than it should be.

The vote back in October 2021 on amending the law would have required ministers to work to reduce the number of overflow discharges.

The majority of the amendment passed but it was edited slightly, removing a requirement for sewage companies to “take all reasonable steps” to ensure untreated sewage is not discharged from storm overflows and to “demonstrate improvements in the sewerage systems”.

MPs who voted to block the amendment argued safeguards already existed and that new measures would cost billions.