In protest against what it perceives to be biased investigations by the prosecution, the opposition Democratic Party is boycotting all National Assembly sessions. At the same time, it is calling for an investigation by an independent counsel into an allegation that the spy agency breached the law by intervening in the 2012 presidential election.

The opposition party had good reason to suspect that the prosecution was unfair in its investigation into an allegation that former President Roh Moo-hyun repudiated the Northern Limit Line, the de facto maritime border in the West Sea, during his 2007 summit with North Korean leader Kim Jong-il. Nonetheless, the party was ill-advised to boycott, of all things, deliberation on the 2014 budget request, which the National Assembly is constitutionally obligated to pass by Dec. 2.

The prosecution publicly summoned Rep. Moon Jae-in of the opposition party, formerly Roh’s chief of staff, to question him about the inexplicable absence of the summit transcript in the National Archives. Then it decided to send a written questionnaire to Rep. Kim Moo-sung of the ruling Saenuri Party and others close to President Park Geun-hye, who were accused of illegally getting access to the classified summit transcript.

When the opposition party cried foul, the prosecution lied, denying it had made any such decision. To complicate matters, Rep. Kim’s aides acknowledged he had received a questionnaire. The prosecution, which had made a fool of itself, now promised to summon Rep. Kim and two other ruling party lawmakers this week.

Now, the opposition party is demanding that an independent counsel be appointed to look into an allegation that the National Intelligence Service and other government agencies engaged in an online smear campaign against its presidential candidate, Moon, during the run-up to the December election.

It will be humiliating for the prosecution if the ruling party is forced to accept this demand, but it would have no one but itself to blame.

But demanding the prosecution conduct fair investigations is one thing. Boycotting deliberations on the administration’s plan to spend 350 trillion won next year is quite another. Only three weeks are left until the constitutional deadline for the passage of the budget bill.

The opposition party will have to participate in the budgetary process immediately. While engaging in the process, it may ally itself with civic groups or appeal to the public, as it puts pressure on the ruling party to agree to its proposal to appoint an independent counsel.