Mr Wutthipong made the call in a letter sent to a well-known red-shirt soothsayer Pruek Prueksunant, better known to social network users as Lung Yim Ta Sawang.
Mr Pruek on Wednesday posted a picture of a handwritten letter claimed to have been sent to him by Mr Wutthipong.
In the letter headlined “Class war begins … against injustice”, the fugitive red shirt called the Constitutional Court an illegal gang and said Wednesday's ruling was expected. He urged members of his red guard army and the United Front for Democracy against Dictatorship (UDD) to joint his fight.
“It’s time to fight. Carry out the planned ideology!! Above the ground, our brothers and sisters who don’t have to fight cases in courts … fight them! Underground, all the stuff needed for a guerrilla unit is in place! I will coordinate the move with the ‘independent reds’,” the letter said.
“No more giving speeches or collecting signatures. For today’s situation, [we] must hunt for their heads only because they have attacked us repeatedly ... I have started … now my brothers and sisters can follow.”
Mr Pruek, a 54-year old native of Lamphun, has established himself as a fortune teller whose predictions about political violence such as bombings or shootings allegedly perpetrated by red-shirt extremists have proven to be accurate.
He often posts his predictions on his Facebook page.
However, Mr Pruek said he did not agree with all the moves suggested by Mr Wutthipong. He added the court decision was still acceptable and did not create a power vacuum, and so the underground war was not needed yet.