Prison officers have been forced to return to work after the Government won a High Court injunction against industrial action.

Thousands of officers stopped working today amid claims jails are 'in meltdown'.

It threw the county's justice system into gridlock, with defendants not being produced for hearings at Oxford Crown Court and Oxford Magistrates.

But at the High Court in London Mr Justice Kerr heard an urgent application for the injunction to 'restrain' the Prison Officers Association (POA) from 'inducing any form of industrial action.'

Among those walking out are prison officers at HMP Bullingdon in Arncott near Bicester.

Prison officers cannot strike by law - and but union bosses said the day of action was to be 'interpreted as a strike'. 

Dave Todd, POA representative for the area, said conditions in prisons including Bullingdon were "volatile and dangerous". 

He added: "We need to act to protect ourselves. It has not come about quickly - it's a build-up over probably years actually. 

"It's just unsafe. To me, prison officers taking this type of action speaks volumes for what's happening inside." 

Daniel Stilitz QC, for the Ministry of Justice, told the judge at the High Court hearing that 'injunctive relief' was being sought against the POA which was 'liable as a trade union for its unlawful inducement'.

Stuart Brittenden, counsel for the POA, said "The POA's position is that the Secretary of State is in breach of their contract in failing to provide a safe place and a system of work, and as such, any instruction to them to continue working in those conditions in this environment is an unlawful one."

The judge said that "on the face of it we have a grave situation".

The demonstration, which began at midnight, comes after a string of high profile incidents at prisons, including an alleged murder, a riot and the escape of two inmates. 

@TheOxfordMail HMP Bullingdon staff out on protest #unityisstrength pic.twitter.com/QN83Nr1PCM

Mr Todd, who said he served with the Army in Northern Ireland in the early 90s, said he found prisons "really daunting" when he first started working in them. 

He added: "I served in Northern Ireland and I felt more vulnerable walking the landings in prisons than I did on the streets of Northern Ireland.

"There's so many weapons within prisons, there's so many prisoners out at once. They can slash, stab and kick, beat, take you hostage if they so wish."

As many as 10,000 staff across the country will participate.

They will provide emergency cover for fires and medical incidents in order to protect prisoners' well-being.

The development comes only days after Justice Secretary Liz Truss unveiled her blueprint for prison reform including a recruitment drive to add 2,500 new officers to the frontline and "no fly zones" to stop drones dropping drugs and contraband into jails. 

An MoJ spokesman said the POA had 'no justification' for this action. 

He added: "We have been engaged in constructive talks with the POA over the last two weeks and have provided a comprehensive response to a range of health and safety concerns. 

"The Government has announced an additional 2,500 frontline officers to help reduce violence in prisons.

"We have well-established contingencies in place to manage prisons and keep the public safe, but we are clear that this constitutes unlawful industrial action, and we will seek remedy in the courts."