A Kent hospital could see a flood of patients from south London attempting to use its services to avoid costly new road charges, an MP has claimed.

Dartford MP Gareth Johnson is warning that Darent Valley Hospital in Dartford will experience "added pressures" this winter following the expansion of the London congestion charge zone.

The Ultra Low Emission Zone was extended in late October to include Lewisham and Greenwich and most of Greater London, charging drivers with non-compatible cars £12.50.

It forms part of London Mayor Sadiq Khan's green plan to tackle excess traffic and toxic air pollution in the capital.

But across the border, Dartford's MP Mr Johnson believes the policy is ill-thought out and will see cash strapped Londoners turn to already stretched local health services in Kent.

Patients in Bexley and Bromley can currently access services at Queen Elizabeth Hospital in Woolwich and University Hospital Lewisham, but both now sit just inside the new ULEZ boundary.

Mr Johnson has warned the expansion of the ULEZ charges to cover these hospitals will push patients unable to pay into north Kent resulting in "serious consequences for the residents of Dartford".

He said: "Unfortunately, people who live in neighbouring towns in south London will choose to use our hospital services because they don't want to or cannot afford to pay £12.50 just to go to their nearest hospital.

“Our town’s hospital is already a very busy place and this will cause added pressure to services.”

Last month, bosses at the Dartford and Gravesham NHS Trust, which covers Darent Valley, urged people to only use A&E if they need emergency treatment and are severely ill after being inundated with hundreds of patients everyday.

Those with non-life threatening conditions were directed to use a new urgent treatment centre at Gravesham Community Hospital in Gravesend.

It comes amid growing problems faced by the local health service.

According to trust figures, in September 11,146 patients were seen at Darent Valley's A&E - an average of 371 people per day.

This represented a 30% increase compared to the 8,537 patients seen in September the previous year.

Mr Johnson is already a strong opponent of the London Mayor’s proposal for the Greater London Boundary Charge, which remains an option according to Transport for London (TfL).

If approved, this additional charge would place a £5.50 levy on vehicles registered outside of London for crossing into London from Kent.

The Tory MP added: “People in Dartford have no say about the ULEZ, or the proposed London Boundary charge, but they will feel the consequences.”

Sue Daniels, a spokesman for Dartford and Gravesham NHS Trust, said: "We thank our MP Gareth Johnson, for his continued support and concern over factors affecting our Trust.

"With the coming winter pressures we have strong contingency plans in place and are working with SECAMB, LAS and our other partners to ensure we can continue to provide a robust and safe service to our community."

ULEZ initially covered the congestion charge zone in central London but was expanded in October to cover larger parts of the capital including Greater London.

Older vehicles and motorbikes that don’t meet the tighter emissions standards – including pre-2015 diesel and pre-2006 petrol vehicles – have to pay £12.50 a day.

NHS patients living in London can apply to TfL to be reimbursed for the ULEZ charge.

However, to be eligible, patients must have a compromised immune system, or require regular therapy or assessment, or recurrent surgical intervention. In addition, they must be clinically assessed as too ill, weak or disabled to travel to an appointment on public transport.

A spokesperson for the Mayor of London said: "We know toxic air pollution in London stunts the growth of children’s lungs and worsens chronic illnesses, such as asthma and our own research confirms that those exposed to the worst air pollution are more likely to be Londoners living in deprived areas and those from Black, Asian and minority ethnic communities.

“The bold action taken by Sadiq since he became Mayor has already led to a 94 per cent reduction in the number of Londoners living in areas that exceed the legal limit for nitrogen dioxide (NO2) levels and the gap between the most and least deprived areas for exposure to nitrogen dioxide has narrowed by up to 50 per cent.

"The health benefits of Sadiq’s policies, including the ULEZ, are expected to avoid almost 300,000 new cases of air quality-related disease, prevent more than one million hospital admissions and save the NHS around £5 billion by 2050.”

Christina Calderato, TfL director of transport strategy and policy, said: “London’s toxic air contributes to thousands of deaths each year and is linked to heart disease, dementia and the stunted development of children’s lungs.

"People’s health and lives are at stake, which is why the expansion of the ULEZ has been implemented now so that 3.8 million Londoners living in the expanded zone can benefit from cleaner air.

"The vast majority of people travelling in the expanded zone already meet the standards, with 87 per cent complying on the day of its launch. It is expected that following its introduction harmful nitrogen dioxide will fall by 30 per cent across the capital.

"We encourage people to use active or public transport if possible rather than pay the ULEZ charge. We know that some people visiting hospitals will need to use a vehicle to get to their appointment, which is why we have an NHS patient reimbursement scheme."