Probation officers will strike against the government's proposals to sell off 70 per cent of the service to murky security corporations.

Napo members voted overwhelmingly in favour of a walkout to fight the justice sell-off.

The 84.4 per cent Yes vote means probation officers join teachers, firefighters, university staff and postal workers in walking out against the Con-Dems' public-service slaughter.

Meanwhile the Prison Officers Association also came out in support of striking against the dangerous fire sale.

POA general secretary Steve Gillan threatened that the union, which is banned from striking, "will take unlawful action" if the government's widespread privatisation policies continue to destroy safety.

Napo has yet to announce the details of the expected one-day strike and is waiting for other probation unions to ballot their members.

General secretary Ian Lawrence said: "Our members have sent a clear message to the government that they will not tolerate the shameless privatisation of the probation service and the serious consequences this will have on communities, offenders, victims and staff."

Mr Lawrence made clear that probation officers would not stand by while the government "decimated the probation service by selling it off to the likes of G4S and Serco."

Not only would the security privateers destroy the base of expertise needed to rehabilitate and reintegrate offenders in order to make "huge profits at the expense of victims, offenders and taxpayers," they will also endanger communities in the process.

The strike will be conducted in solidarity with other unions also battling the Con-Dems' privatisation agenda, Mr Lawrence said.

"Solidarity is the way to win this dispute. Not only internally but our brother and sisters in other unions as well.

"Privatisation continues unabated - communities are suffering and more people are unemployed with no hope of a decent job. While all the time ministers say: 'The private sector's creating more opportunities than ever'.

"You know what type of jobs they are - low pay with zero-hours contracts - the type of stuff the privateers want to introduce in probation."

Mr Gillan said these conditions were already been felt in the prison service, with officer numbers being slashed and assaults increasing.

There are already 14 private prisons in Britain.

"Probation officers have made the right decision," said Mr Gillan.

"I don't believe that G4S, Serco or Sodexo have the expertise to deal with the risk factors on behalf of the general public.

"There's some good people working for those companies, who I represent, but the reality is privatisation in the criminal justice system is rotten to the core."