Nuneham viaduct closure rail disruption to last until June

Nuneham viaduct carries trains across the River Thames in Oxfordshire

A main rail line is expected to remain closed until June because of work on an unsafe viaduct, Network Rail has said.

Nuneham viaduct near Abingdon, Oxfordshire, was shut on 3 April because of instability.

The bridge over the River Thames carries CrossCountry and Great Western Railway services, as well as freight trains to and from Southampton Docks.

Network Rail said it hoped a temporary structure would allow trains to run between Didcot and Oxford by 10 June.

Pictures from a leaked Network Rail document show cracks in the viaduct brickwork

GB Railfreight said the viaduct was a "key corridor" for its rail freight services and would result in "serious implications for the transportation of construction materials, fuel and consumer goods".

A spokesperson said: "While we are doing what we can to mitigate the effects of the disruption, it is inevitable that some commodities will end up being transported by road.

"Given the importance of this line, it is imperative that it's fixed as soon as possible."

Last week, Maggie Simpson OBE, director general of the Rail Freight Group, told the BBC that 40 freight trains ran on the route every day - the equivalent of around 2,000 lorries.

The route is used by freight trains to and from Southampton Docks

Network Rail spokeswoman Nicky Hughes said the temporary structure being built would stabilise the viaduct after "increasingly significant movements" forced its closure.

She said: "That involves piling down into the Thames... get a temporary structure over the bridge, take the weight off it to enable us to run trains back over it at a reduced speed."

Previously Network Rail said the disruption would last until late April.

The track operator said the viaduct failed despite recent repairs and following the wettest March in more than 30 years.

Rail firms are running revised timetables and replacement buses for passengers while freight trains are expected to be diverted via west London.