The warning comes a day before defence minister Adam Ingram is due to meet unions representing MOD civilian staff in the region whose jobs are under threat.

Up to 6,500 military and defence posts could be affected by plans to scale down the security profile in Northern Ireland. The unions have called on MOD and the Northern Ireland Office to provide additional support to help MOD civilian staff retrain or seek new jobs.

Under plans revealed in August by the Northern Ireland Secretary, military support to the Police Service of Northern Ireland will be drawn down with the permanent military presence reduced to no more than 5,000 personnel by August 2007.

Within the same timescale, the Royal Irish Regiment will also be disbanded and the number of MOD sites will be reduced from 40 to no more than 14 core sites, with a knock-on effect on the number of civilian posts and other jobs in the supply chain.

But while the security reduction is welcome evidence of the success of the peace process, Prospect, GMB, Amicus, the Public and Commercial Services union, and the T&G fear that closures and job losses on this scale will be devastating for individuals and communities, particularly within remote areas with few other employment prospects are already sparse.

Union spokesperson Ann Jarvis said: "MOD and the Northern Ireland Office need to ensure this process is handled properly and with the right support, otherwise releasing this many people into the job market in Northern Ireland will cause major problems for those entering the market and for existing job seekers.

"The potential negative impact on Northern Ireland could eclipse the loss of Rover in the West Midlands. Although the figures are similar, the losses will occur over a far less industrialised and populated area."

Recent figures from the Department of Enterprise, Trade and Investment show that unemployment rates for people in Northern Ireland aged 18–24 are three times higher than the UK national average, with the overall number of people classified economically inactive also higher than the rest of the UK.

Peter Allenson, chair of defence estates industrial Whitley committee trade union side, said: "Experience from other large plant closures and redundancy programmes in the UK shows that managing the change makes a huge difference not only to the redundant workforce but also the local surrounding communities."

The unions cite examples such as MG Rover, Corus, and the foot and mouth disease. Following the collapse of MG Rover, the government provided £150m in aid to regional regeneration agencies in the West Midlands to help Rover employees retrain or find other jobs.

In 2001 a major restructuring of the steel company Corus resulted in the loss of 7,000 jobs. Funds provided through the Department of Trade and Industry Partnership Fund provided a range of training and retraining packages, including one run by the gas distribution company Transco to retrain Welsh steel workers in gas and heating skills. Similarly, the government’s Development Fund for Rural Renewal aided regeneration of Britain’s rural economy after the foot and mouth crisis.

The unions are calling for:

• Investment in the community in Northern Ireland to make the peace process feasible for the prosperity of the province as a whole.
• A redundancy and enhanced severance package which recognises the service, loyalty and commitment of the MOD civilian workforce in Northern Ireland. This should include flexibility over the date staff leave to ensure no detriment to the terms of the severance package, and a resettlement and assisted moving package for staff who have to move home to find employment.
• A dedicated MOD human resources team to deal with the transition and provide hands-on assistance in obtaining non-MOD work including help with CVs, training assessment and work placements.
• Full training and a commitment to training and retraining to enable staff to find jobs outside the MOD.
• Collaboration between the MOD and the Strategic Investment Board to identify what skill shortages and training needs have been identified in Northern Ireland and also positive investment in new industries.
• An aftercare package for individuals who have difficulty finding employment or adjusting to life after the MOD.