Definition and legal basis:

Main intervention and secondary intervention are procedural instruments that allow third parties to participate in ongoing civil proceedings. Both institutes are regulated in the Code of Civil Procedure (ZPO): the main intervention in Section 64 ZPO and the secondary intervention in Sections 66-71 ZPO. They serve to protect the interests of third parties in a legal dispute and to ensure the efficient administration of justice.

Main intervention:

The main intervention, also known as an intervention action, enables a third party to assert their own claim to the subject matter of the dispute. The main intervener brings an action against both parties to the original legal dispute. The prerequisites are

1. a pending legal dispute between two parties
2. The third party’s own claim to the subject matter of the dispute
3. Bringing an action against both original parties

The main intervention leads to a new, independent lawsuit. The original legal dispute can be suspended at the request of a party until a decision has been made on the main intervention (Section 65 ZPO).

Ancillary intervention:

In an intervening party, a third party (intervening party or intervener) joins a party to the ongoing legal dispute in order to support it. The prerequisites are

1. a pending legal dispute
2. A third party’s legal interest in a party prevailing
3. Declaration of intervention by the intervening party

The intervening party does not become a party to the legal dispute, but can take legal action in favor of the supported party.

Comparison and differentiation:

1. party status:
– Main intervener: Becomes a party to a new lawsuit himself
– Intervener: Remains a third party, does not become a party

2. procedural status:
– main intervener: conducts its own proceedings
– intervener: supports an existing party

3. status of claim:
– main intervener: asserts own claim
– secondary intervener: supports third-party claim

4. frequency in practice:
– main intervention: rare
– secondary intervention: more frequent, especially in connection with third-party notices

Practical significance:

The main intervention plays a subordinate role in practice, as a third party can often wait and see how the original lawsuit turns out without losing its own rights. Ancillary intervention, on the other hand, is of greater practical relevance, particularly in the following areas:

1. liability issues: e.g. accession of a liability insurer
2. Warranty law: Joinder of a supplier in a lawsuit against the manufacturer
3. Company law: Joinder of shareholders in actions for rescission
4. Tenancy law: Joinder of the landlord in lawsuits between the main tenant and subtenant

Effects of secondary intervention:

The most important consequence of intervening is the intervention effect (Section 68 ZPO). It has the effect that the intervening party must accept the decision of the lawsuit in subsequent proceedings. This is intended to avoid contradictory decisions and serves the purpose of procedural economy.

Special procedural features:

1. admission: The admissibility of the intervening party is decided by order if a party objects (section 71 ZPO).
2. appeal: The intervening party can appeal independently, even against the will of the supported party.
3. costs: The intervening party bears its own costs, but can demand reimbursement of costs from the opposing party if the supported party wins.

Summary:

Main intervention and secondary intervention are important procedural instruments for safeguarding the interests of third parties in civil proceedings. While main intervention is rarely used in practice, secondary intervention is a frequently used means of involving third parties in ongoing proceedings and ensuring uniform jurisdiction. Both institutions contribute to the efficiency of the administration of justice by enabling the bundling of related disputes and helping to avoid contradictory decisions.