The strike, Germany's largest in decades, is expected to cause widespread disruption on railways and at airports in Europe's largest economy.
"The people are not only underpaid, they are hopelessly overworked," Frank Werneke, head of the Verdi labour union, told Bild am Sonntag.
The strikes, scheduled to primarily start just after midnight and affect services throughout Monday, will be the latest in months of industrial action and protests that have hit major European economies as higher food and energy prices dent living standards.
The Verdi union is negotiating on behalf of around 2.5 million employees in the public sector, including in public transport and at airports. Railway and transport union EVG negotiates for around 230,000 employees at Deutsche Bahn and bus companies.
Verdi is demanding a 10.5% wage increase, which would see pay rising by at least 500 euros ($538) per month, while EVG is asking for a 12% raise or at least 650 euros more per month.
"The strike is necessary to make clear to employees that we will vehemently stand up for our demands," Werneke was quoted as saying.
"It is a matter of survival for many thousands of employees to get a considerable pay rise," he said.
($1 = 0.9295 euros)
(Reporting by Tom Sims and Klaus Lauer; Editing by Raissa Kasolowsky)
