1. The part concerning the claim for nullification of the contract in this case shall be dismissed.

2. The plaintiff's remaining claims are dismissed.

3...

1. Basic facts

A. On December 22, 2014, the Plaintiff submitted to the Defendant a contract guarantee under the name of the Non-Party Construction Mutual Aid Association (hereinafter “Non-Party Construction Mutual Aid Association”) related to the contract deposit under Section 4(1) of the General Conditions of the Construction Contract on the same day, setting the contract deposit of KRW 111,387,00 for the construction cost, from December 23, 2014 to April 22, 2015 (hereinafter “instant contract deposit”); and on the same day, submitted to the Defendant a contract guarantee under the name of Non-Party Construction Mutual Aid Association (hereinafter “Non-Party Mutual Aid Association”) related to the contract deposit under Section 4(1) of the General Conditions of the Construction Contract.

B. On April 2, 2015, the non-party union paid KRW 16,708,050 to the Defendant as the contract deposit under the guarantee insurance contract on the above written guarantee (hereinafter “instant guarantee insurance contract”). After that, the non-party union exercised the security right to the investment certificates equivalent to KRW 2,324,570 in the name of the Plaintiff, and received KRW 14,383,480 from the Plaintiff on September 1, 2015, and recovered all the said contract deposit from the Plaintiff.

[Reasons for Recognition] Facts without dispute, Gap evidence Nos. 1, 8, 10, 11 (including additional numbers) and the purport of the whole pleadings

2. The part demanding nullification of the contract

A. On the grounds delineated below, the Plaintiff asserts that the instant construction contract was null and void and that there was a benefit to seek confirmation, and sought nullification of the said construction contract.

① Since children of a local council member at the time of entering into the instant construction contract were the Plaintiff’s representative director, the Plaintiff cannot enter into the instant construction contract under a negotiated contract pursuant to Article 33(2)4 of the Act on Contracts to Which a Local Government Is a Party (hereinafter “the Act”), and there was no qualification for participation in the contract pursuant to Article 92 of the Enforcement Decree of the Act on Contracts to Which a Local Government Is a Party (hereinafter “Enforcement Decree”), and thus, the instant construction contract, which was concluded through a negotiated contract, was concluded through a bid for the selection of a