Scotland's largest police force is inviting all of its civilian staff to apply for voluntary redundancy in a bid to cut up to 600 jobs.
Strathclyde Police also aims to cut 200 officer posts through early retirement.
The measures, approved by Strathclyde Joint Police Authority, aim to rein in a projected budget shortfall of about £128.5m by 2015.
Unions have said they could take industrial action over the civilian job losses, which affect 25% of staff.
A Scottish government statement said the police authority's decision had been based on "the current economic climate and not on a set budget".
A government spokesperson added: "The Scottish Government has provided record levels of police funding this financial year, £1.4bn - a 20% rise since 2006-07.
"There are already more than 1,000 additional police officers in Scotland since this government came into office, which has helped reduce recorded crime to a 30-year low."
A report before the police authority, which assumed a 24% reduction in funding between 2011 and 2015, stated that without cost-cutting measures the force would face a budget deficit of almost £128.5m.
It recommended a number of measures, including civilian staff redundancy, a pay freeze, an ongoing freeze on police recruitment and a review of staff terms and conditions.
The report stated that with an additional 10% cut to non staff budgets, the scale of post reductions could be cut from 1,208 to about 800 - 600 civilian and 200 police posts.
It said: "The informed view is that across the public sector funding cuts will be much greater than previously expected.
"With approximately 88% of current gross budget resources allocated to payroll costs, the impact of cuts will be particularly severe and inevitably have a significant impact on payroll related elements of expenditure - both in terms of numbers of staff/officers and conditions of service."
Unison branch officer Gerry Crawley said that if Strathclyde Police did not achieve its savings targets up to 800 civilian posts could go in addition to 400 police posts.
"Our big fear is that there is going to be compulsory redundancies," he said.
"The only decision that the police authority took today was to effectively cut the voluntary redundancy package on offer to staff.
"Although the cash offer is still unaffected the pension terms have been reduced. How do they expect to achieve 600 voluntary redundancies this way?"
Mr Crawley said Unison had agreed to make a joint approach, with Strathclyde Chief Constable Stephen House, to the Scottish government over the cash crisis facing the force.
He said the scale of the cuts being implemented meant that industrial action "could not be ruled out" and pledged to "fight for every job" under threat.
The scale of the projected budget shortfall facing Strathclyde Police is likely to become clearer after the Scottish government's spending review in October.
The voluntary redundancy package on offer to staff will run until the end of October.
Once the uptake is known, with the likely projected budget shortfall, the force will have to decide whether to pursue voluntary redundancy of support staff.
If any industrial action is called in response to such a decision it is likely to be next year.