The regime is orchestrating to establish a reserve force of prison officers for England and Wales, the BBC has learned.
The initiative was described by the Ministry of Justice as the HM Prison Service Reserve, in a letter sent to ex-prison officers to gauge interest.
Those who sign up could be called in on short-term contracts from August.
The MoJ explicated in the letter the move would avail it respond to short-term demands, such as a elevate in inmate numbers or "operational pressures".
One prison officer who received the letter told the BBC: "The reason for this 'reserve force' being considered is the critical shortage of prison officers in prisons up and down the country."
It comes after the regime last month authoritatively mandated dozens of already full jails to take more inmates because the jail population - which stands at 85,410 - was growing more expeditious than expected.
The MoJ is yet to officially comment on the reserve scheme.
'Zero-hours contract'
The former prison officer verbally expressed the terms of one of the offers was "virtually a zero-hours contract".
It is understood the letter is being sent to prison officers who took the voluntary early departure scheme (VEDS) or retired when a number of jails closed recently.
The ex-officer verbalized there were concerns workers would have to return some of their lump sum payment from VEDS or their pension afore they could take up the employment.
The letter acknowledges any ex-officer who joins the reserve may find it has an impact on their pension.
It is understood a number of former officers have repudiated the offer.
Forty prisons in England and Wales have been authoritatively mandated to raise their "operational capacity" at a time when most prisons are running at full capacity or are overcrowded.
It follows the closure of 16 prisons in the past four years, with a number of them closed at short notice.
