Officers at Lincoln Prison have vowed to fight to save their jobs and say they would consider a major protest if ministers close the jail.
Around 200 members of staff at the Greetwell Road site say they are in limbo and have demanded immediate answers from the Ministry of Justice.
The Echo revealed at the start of the month how a review of the 140-year-old site is being carried out in Whitehall.
Justice Secretary Chris Grayling may decide to downgrade the prison from a category B to a category C service or shut it altogether.
Should this happen, it may be replaced with an immigration centre.
Paul Wray, branch chairman of the Prison Officers Association at HMP Lincoln told the Echo: "We are in complete limbo.
"We have set up our own petition alongside that of the Lincolnshire Echo – who we thank for its support.
"If that doesn't prove successful then we will have to start thinking about protests.
"We haven't planned anything yet but we are determined to fight very hard for our jobs.
"Lincoln needs a prison at the end of the day.
"It is the uncertainty over our future that is the most annoying thing.
"Many of the prison officers have families and not knowing whether you are going to have a job in a few months time makes for very nervous times – it isn't fair.
"We have a new management team here and we want to keep our jobs."
Meanwhile, the Ministry of Justice again refused to reveal any more details about its review into the prison's future this week.
Now, Mr Wray has urged the Ministry of Justice to make its final decision as soon as possible.
"We just have to know what is going on," added Mr Wray.
"We need answers as soon as possible.
"We want to know what is going on, how many days or weeks we have left and whether we need to start thinking about other jobs or developing skills in something completely different.
"Potentially prison officers, who may not have a job soon, are currently missing out on other opportunities.
"The problem we face, and we are realistic enough to know this, is that the public sector is cutting jobs left, right and centre."
Mr Wray hopes the petition, that will be in Lincoln city centre for people to sign on Saturday, attracts thousands of signatures.
He revealed he may also write a letter to the Government, outlining his disappointment.
"Hopefully the Government will see sense and keep our prison open.
"The decision process so far has been a snap one.
"The Government has seen a quick opportunity to save some money but has ignored the long term implications of this.
"Losing the prison would surely mean the end of Lincoln Crown Court and together that would be a huge blow to a county with the geography and size of Lincolnshire.
"Quite simply, we want clarification as soon as we can get it and our futures sorting out once and for all."