The start of the strikes represents a further escalation of a dispute between Europe's top car maker and its workers over mass lay-offs, pay cuts and possible plant closures - drastic measures the company says it cannot rule out in the face of Chinese competition and cooling consumer demand.
Labour representatives at VW had on November 22 voted for limited strikes at German operations from early December after talks over wages and plant closures failed to achieve a breakthrough.
"If necessary, this will be the toughest collective bargaining battle Volkswagen has ever seen," IG Metall negotiator Thorsten Groeger said in a statement.
The car maker said it continues to rely on constructive dialogue to find a sustainable solution.
"Volkswagen respects the right of employees to take part in a warning strike," a spokesperson said in reply to the union's announcement, adding that the company had taken steps in advance to ensure a basic level of supplies to customers and minimise the impact of the strike.
Warning strikes in Germany usually last from a few hours.
The union had last week proposed measures it said would save 1.5 billion euros ($A2.4 billion), including forgoing bonuses for 2025 and 2026, which Europe's top car maker dismissed.
Volkswagen has demanded a 10 per cent wage cut, arguing it needs to slash costs and boost profit to defend market share.
The company is threatening to close plants in Germany for the first time in its 87-year history.
"Volkswagen has set fire to our collective agreements and instead of extinguishing this fire in three collective bargaining sessions, the management board is throwing open barrels of petrol into it," Groeger said.
An agreement not to stage walkouts had ended on Saturday, IG Metall said, enabling workers to carry out warning strikes from Sunday across VW AG's German plants.
"Warning strikes will start at all plants from Monday. How long and how intensive this confrontation needs to be is Volkswagen's responsibility at the negotiating table," Groeger said.
Labour representatives and management will meet again on December 9 to carry on negotiations over a new labour agreement for workers at the German business - VW AG - with unions vowing to resist any proposals that do not provide a long-term plan for every VW plant.
