One of Britain’s ‘biggest ever’ fly tips has appeared in Oxfordshire and is a massive 500ft-long mountain of abandoned rubbish, prompting activists to condemn the ‘environmental catastrophe’.

The 20ft-high pile of hazardous rubbish was illegally dumped in a field next to the A34 and River Cherwell near Kidlington in Oxfordshire.

It is believed the waste was dumped in one go and it has since been described by an MP as ‘threatening an environmental disaster’.

It was discovered last month by horrified anglers and contains plastic, foam and wood. It is not known exactly when the mountain appeared.

Dramatic drone footage taken from above shows the sheer enormity of the rubbish, located just metres from Oxfordshire’s River Cherwell. 

Charity Friends of the Thames told the BBC: ‘This is an environmental catastrophe unfolding in plain sight.

‘Every day that passes increases the risk of toxic run-off entering the river system, poisoning wildlife and threatening the health of the entire catchment.’

The Environment Agency has confirmed a probe has been launched and has encouraged anyone with any information to get in touch as soon as possible.

The 20ft-high pile of hazardous rubbish was illegally dumped in a field next to the A34 and River Cherwell near Kidlington in Oxfordshire

Some of the rubbish has fallen down because it was so tall, which has left the waste just five metres from the river

The 150ft-long dump has been described as one of the biggest fly tips ever seen in Britain

The fly tip was discovered last month by horrified anglers and contains plastic, foam and wood

Much of the waste appears to have been shredded and mixed up with earth

It is hard to distinguish any particular bits of waste as it appears to have been shredded, and earth mixed in. 

Some of the rubbish has fallen down because it was so tall, which has left the waste just five metres from the river.

The fly tip was first discovered by the Kidlington Angling Society, and was has been described by activists as ‘horrendous’.

Calum Miller, Liberal Democrat MP for Bicester and Woodstock, raised the issue in Parliament.

Addressing MPs on Thursday, he said: ‘Criminals have dumped a mountain of illegal plastic waste… weighing hundreds of tonnes, in my constituency on a floodplain adjacent to the River Cherwell.

‘River levels are rising and heatmaps show that the waste is also heating up, raising the risk of fire.

‘The Environment Agency said it has limited resources for enforcement, that the estimated cost of removal is greater than the entire annual budget of the local district council.’

Responding, environment minister Mary Creagh said Labour inherited a ‘failing’ waste system that has caused an ‘epidemic of illegal fly-tipping’. 

A spokesperson for the Environment Agency said: ‘Specialist officers are investigating waste dumped near the A34 at Kidlington. Their role will be to find who left the waste there and take appropriate action.

‘We share the public’s anger about incidents like this, which is why we take action against those responsible for waste crime. Anyone with information about this incident, or if they suspect waste crime elsewhere, can call the Environment Agency’s 24-hour incident hotline: 0800 807060.’