A judge’s refusal to quash felony abuse of power charges will not derail – or even delay – former Texas governor Rick Perry’s preparations for a possible 2016 presidential run, the Republican said on Wednesday.

“We’re moving right along as expected,” Perry said, mentioning his visits to the early primary states of Iowa and South Carolina in the last week. He also reiterated at a news conference in an Austin hotel his pledge to announce his decision on a White House campaign in May or June.

A day earlier, state judge Burt Richardson refused to quash two indictments against Perry on constitutional grounds. Perry’s defense team has promised a swift appeal, but said a higher court may take as many 60 days to rule on it.

Perry faces charges of abuse of official power and coercion of a public servant, an indictment brought in August by a grand jury in Austin, a liberal enclave in otherwise largely conservative Texas.

He is accused of publicly threatening – then making good on – vetoing $7.5m in state funding for a public corruption division within the office of Travis County District Attorney Rosemary Lehmberg. That came after Lehmberg, a Democrat whose county includes Austin, rebuffed Perry’s calls to resign following her drunken driving conviction.

Perry said on Wednesday he would issue the veto again if given the chance, saying Richardson’s ruling “doesn’t change the constitutional argument from day one” that a governor has the power to veto anything he chooses.

“I used that authority lawfully and legally,” Perry said, flanked by a pair of defense attorneys. He added that his rights to free speech were as valid as any American’s and that “this continued prosecution flies in the face of that protection and it directly assaults the United States constitution”.

Perry was Texas’ longest-serving governor but his 14-year term ended last week. He’s already spent $1.1m of his campaign funds defending himself in the case.

“I know that my actions were right,” Perry said.