Park then fired a number of her cabinet members and the prime minister. In particular, the sacking of the prime minister, Hwang Kyo-ahn, resulted in controversy, due to the claim that his firing was carried out via a text message. The Supreme Prosecutors' Office of Korea (SPO), in laying charges against Choi and two former presidential aides, alleged that Park colluded with the three in certain criminal activities. The president would be questioned by prosecutors, the first time this has occurred with a serving South Korean president. Following the scandal, there was a series of massive demonstrations that started in the first week of November 2016. On 29 November 2016, Park offered to resign as president, and invited the National Assembly to arrange a transfer of power. The opposition parties rejected the offer, accusing Park of attempting to avoid the process of impeachment.