The campaign for the July 30 parliamentary by-elections is in full swing, with major parties mobilizing all of their resources to win what are called the “mini general elections,” partly because there are 15 seats up for grabs, the most in the history of parliamentary by-elections.

With partisan fighting escalating as the poll day draws nearer, a hot issue has surfaced over an opposition candidate, Kwon Eun-hee, a former police officer who stirred up an intense political dispute last year with her whistle-blowing regarding a probe into alleged political interference by the spy agency.

Kwon claimed that her boss at the time, the Seoul police chief, pressed her to tamper with the investigation into the spy agency’s online political activity during the last presidential election. Both the lower and appeals courts found the police chief not guilty.

The opposition New Politics Alliance for Democracy’s nomination of Kwon as a candidate for the by-election in a district in Gwangju had already invited criticism from the ruling Saenuri Party that the opposition camp was compensating her for whistle-blowing.

Then came the controversy over her wealth, more specifically her husband’s. The Korea Center for Investigative Journalism, an online media outlet, broke the story, saying Kwon’s husband’s wealth, mostly real estate holdings, is estimated at about 3 billion won, far more than the 700 million won that was reported to the NEC. It also raised the possibility of tax evasion.

Kwon said that as required by law, she reported only the face value of the stocks in real estate firms owned by her husband and that there was some carelessness, but she never intended to underreport her family’s wealth.

Along with a previous allegation of plagiarism on her master’s thesis, the latest controversy has become a key election issue as the ruling party and conservatives are trying to make it a central election issue.

Excessive partisan fighting during election campaigns, which is often accompanied by slander and false accusations, is something that is frowned upon, yet the allegations involving Kwon’s husband arouse some suspicions.

That being the case, the controversy should remind us of the necessity for parliamentary candidates to go through public vetting just as tough as that undergone by senior officials nominated by the president.

It was only recently that President Park Geun-hye’s nominees for prime minister and other Cabinet members bowed out, one after another, amid public and opposition accusations of ethical problems. Opposition lawmakers were at the forefront of the scrutiny and consequent political offensive against the nominees and the president.

Many people who see parliamentary confirmation hearings on television wonder how many of the lawmakers grilling nominees would be able to pass public screening and the parliamentary hearing if they were put through the same process.

NEC data shows that of the 55 candidates in the forthcoming by-elections, 30 have criminal records. One has been convicted as many as five times, and some candidates have been convicted of such heinous crimes as bribery, fraud and physical assault. Drunken driving offenses are very common.

Unlike Kwon’s case, which has been put in the spotlight because of her national prominence, ethical problems with most candidates for the National Assembly and local councils go unnoticed by and large. It is nonsensical that those entrusted to check the qualifications of civil servants are not required to have the same ethical standards as those they examine. One of the first things to do could be to strengthen the rules on eligibility for elected offices.