Salaries for ministers and senior officials would be cut by up to 20 percent and Zimbabwe would close some embassies abroad.
Zimbabwe's main public service union on Friday rejected government plans to cut 25,000 jobs and suspend annual bonuses, saying that would hurt workers already struggling to make ends meet.
The Apex Council, a grouping of all state sector unions, demanded talks with the government over the plan that Finance Minister Patrick Chinamasa has said is essential to ensure the country can keep paying its staff.
"We believe these measures are ill-conceived and can only further entrench the doom and gloom that has become the lot of the average civil servant," said Cecelia Alexander, head of the Apex Council which called a two-day walkout by teachers, doctors and nurses over pay delays in July, part of the biggest strike in Zimbabwe in 10 years.
In a budget statement on Thursday, Chinamasa said state sector wages took up 97 percent of total revenues collected between January and June, a situation that could destabilise the economy.
It also meant the government risked being unable to pay salaries, Chinamasa said, proposing the suspension of annual bonuses for state employees in 2016 and 2017 to save $180 million annually.
Last year, Chinamasa made similar proposals but was forced to back down by President Robert Mugabe who told him to find the money elsewhere.
Under Chinamasa's plan, the civil service would shed 25,000 jobs, reducing the workforce to 273,000 by the end of 2017. Salaries for ministers and senior officials would be cut by up to 20 percent and Zimbabwe would close some embassies abroad.
Unable to get funds from international lenders, Zimbabwe is in its worst financial crisis since adopting the U.S. dollar in 2009. Economic difficulties have fueled political tensions, with anti-government protests over cash shortages and unemployment.
Chinamasa is leading Zimbabwe's re-engagement with lenders including the International Monetary Fund and World Bank which are demanding cuts in the wages bill and the clearance of $1.8 billion in debt arrears before they agree to new funding.