[14] On 3 May 2012, the party internal investigation revealed that wide-ranging irregularities occurred in selecting UPP's proportional representation candidates.

[19][20] According to Amnesty International, the UPP's ban raised "serious questions as to the authorities' commitment to freedom of expression and association".

[26] On 5 September 2013, South Korea's intelligence agency, NIS, accused UPP lawmaker Lee Seok-ki of plotting a pro-North Korean rebellion.

South Korean prosecutors subsequently indicted Lee on charges of plotting a pro-North Korea rebellion to overthrow the government, saying his plan posed a "grave" national security threat.

[28] However, UPP lawmakers say that while the meeting in question did take place, they had no intention of destroying South Korean government infrastructure.