Around 300,000 hectares of UK soil are thought to be contaminated with toxins – such as cadmium, arsenic and lead - but the Department for Environment, Food & Rural Affairs (Defra) has withdrawn capital grant funding for local authorities to clean up this contamination.
Without Defra's funding councils are less likely to proactively investigate potential contamination, despite the potential public health threat this poses.
Those findings are published in a new report on the health of UK soil, produced by the Environmental Audit Committee after gathering evidence from soil health experts.
The committee, made up of cross-party MPs, has called for Defra to set new funding for contaminated land remediation at the level of the old scheme.
Committee chair Mary Creagh MP said a reliance on the planning system to clean up contaminated land may be fine where land values are high, but poorer areas are likely to see contaminated land go untreated.
"Councils simply do not have the resources to investigate which sites are contaminated. Ministers must rethink their decision to phase out contamination clean up grants."
The committee heard evidence that some local authorities now have no budget to investigate contamination, and that it would be "reckless" to investigate sites if there is no funding for remediation.
The soil health report also warns that failing to prevent soil degradation could lead to increased flood risk, lower food security, and higher carbon emissions.
Soil is a "Cinderella environmental issue", said committee chair Mary Creagh MP.
"It doesn't receive as much attention as air pollution, water quality or climate change. But, whether we realise it or not, society relies on healthy soil for the food we eat, for flood prevention, and for storing carbon.
"The Government says it wants our soil to be managed sustainably by 2030, but there is no evidence that it is putting in place the policies to make this happen."
The report also calls for the Government to set out plans to increase the amount of carbon retained in the soil and to take tough action to tackle land use practices which degrade peat, such as the burning of blanket bogs.
And it calls for stronger rules around regulating agricultural soil health, which currently focus on preventing damage to soil rather than encouraging their improvement.
Defra's current "ad hoc approach" to conducting soil health surveys is inadequate, the report adds.
"The Government should introduce a rolling national-scale monitoring scheme for soil health to ensure that we have adequate information about the state of the nation's soil."