In an emotional statement laced with bitterness, Yongyuth said his rivals framed him in order to curtail his political career.
"I will fight to the full extent of the law to expose how I was setup for injustice and I hope no one would ever again attempt to destroy an individual or a party by abusing the judicial system," he said.
He recounted how he was detained for two weeks following the September 19 coup and that he was intimidated by security authorities after his release.
This prompted him to go abroad to further his studies, he said. After he returned home, which coincided with the December 23 election, he decided to work with his allies to forge reconciliation and bury the animosity between former prime minister Thaksin Shinawatra and the elder figures in society.
In regard to events leading to the votebuying charges, he said he welcomed his party leader Samak Sundaravej to visit Chiang Rai constituents even though authorities tried to disrupt the People Power rally by setting up road blocks in October.
After the official launch of campaigning on October 25, a group of kamnan and village headmen called on him at home, but only agreed to meet them later at a hotel. He moved the venue and refused to pay for their meals for fear of violating electoral rules.
He claimed he saw some soldiers taking pictures of him and village headmen while saying what he believed to be a joke that the pictures would be meant as evidence to red card him. He said the soldiers took pictures of him again in November. On both occasions, he was not an electoral candidate yet.
Later a rival candidate notified the Election Commission that he paid the group of kamnan in exchange for votes. He later learnt that this group of kamnan gave their statements to Special Branch police officers and soldiers. He claimed that the questioning procedures were illegal and the statements were fabricated.
Yongyuth said it could not make any sense as to why he would pay nine kamnan and expect them to be able to ensure his victory in Chiang Rai.
He said one of his nine accusers had a dubious history as a suspected drug trafficker before the coup who might have made a deal to clear drug charges by framing him.
He also said a senior police general tried to coerce a local officer, Lt Col Supoj Saengphet, to raise frameup charges against him in a scam to dismantle the main coalition party.
Yongyuth pledged to suspend his speaker's duties until he could clear his name, but would continue to perform his job as an MP.