Mr Jatuporn was speaking at a UDD press conference called to give an upate on the political situation.
He said the Democrat Party's announcement to boycott the Feb 2 election was not exciting because this had been expected. "Maybe they think they can defeat the Thaksin regime by not competing in the election," he added.
Mr Jatuporn urged the Election Commission to find ways of making the election clean and fair.
He also called on all the armed forces commanders to keep their word.
"You have said there will not be a coup. You must keep your word. Without a military coup, Mr Suthep will never bring down this government," Mr Jatuporn said.
Weng Tojirakan, another UDD core member, said Mr Suthep should call off the protest and accept the prime minister's proposal for all political parties to jointly reach an agreement that there will be political reform after the election.
"The Democrat Party is not excluded if it wants to see political reform. The prime minister has opened a way for it to join. If not, you could be branded as a political hooligan," Mr Weng said.
UDD chair Tida Thawornseth said this was the third time the Democrat Party had boycotted an election.
"This party should be disbanded and its members should then join the PDRC. By not taking part in the election, the Democrat Party is joining hands with the rebels to topple democracy," she said.
"On Dec 23, the first day for party-list candidate registration, we will see if the rebels stir up violence or intimidate the candidates," Ms Tida said, referring to PDRC leaders.
She called for the people to support the election and not to allow political hooliganism to prevail. She predicted there would certainly be strategic moves to obstruct the election, so the government must make sure it maintains peace and order.
"The UDD is not fighting for any party. We will rise to fight only if there is a coup," she said.