The Greens have failed to force debate on a bill giving all workers two weeks' paid pandemic leave.
Despite gaining Labor's support to change the Senate's agenda, the government secured enough crossbench votes to shoot down the push.
Under the plan, workers without access to sick leave who need to isolate because of coronavirus could access government-funded time off.
Greens senator Mehreen Faruqi said all workers needed 14 days of pandemic leave to avoid people choosing between health and livelihoods.
"We don't have to wait for a disaster to do that. We can have better public health in our country and we can support our workers better as well," she told parliament on Wednesday.
"It can help save lives."
Government Senate leader Mathias Cormann said the government had important legislation on its agenda.
"This is an attempt to disrupt the orderly operation of the Senate," he said.
"Australia is going through a pretty difficult period and this is not a time to play procedural games."
The Senate returned to debating a bill to clarify law around federal political donations being used for state purposes.
Independent Jacqui Lambie said the government was more concerned with cash to win seats than Australians' health.
"We are going through such a crisis in this country, such an economic crisis, and these major parties have made a dirty, filthy, little deal to talk about electoral matters," she told senators.
Labor frontbencher Don Farrell said parliament was living in a parallel universe by giving the electoral bill precedence over pandemic leave.
"The Greens and Labor maintain that the most important issue that this country now faces is dealing with the issue of paid pandemic leave," he said.