The leading Blue Dog Coalition health care negotiator vowed Tuesday to vote against any reform bill that contains a public insurance option, citing opposition from his constituents during the August recess.

Rep. Mike Ross (D-Ark.), the chairman of the Blue Dog health care task force, had previously backed a public insurance option in a breakthrough deal with Energy and Commerce Chairman Henry Waxman (D-Calif.) and House leaders, but that agreement now appears to be in tatters.

Ross made the declaration in a newsletter to his constituents.

“I have been skeptical about the public health insurance option from the beginning and used August to get feedback from you, my constituents,— Ross said. “An overwhelming number of you oppose a government-run health insurance option and it is your feedback that has led me to oppose the public option as well. … A government-run public option is the wrong direction for health reform in this country and I will oppose it in the U.S. Congress.—

Ross also said that “we must insist on commonsense tort reform as a means of controlling frivolous and costly lawsuits— — something the current bill does not include.

Ross’ statement complicates matters greatly for Speaker Nancy Pelosi (D-Calif.), who vowed as recently as last week that a bill could not pass the House without a public insurance option, which is strongly backed by the Congressional Progressive Caucus.

Ross was the lead negotiator in July during the Energy and Commerce Committee markup of its health care bill. That panel agreed to a measure that keeps a public insurance option but forces it to negotiate rates with providers rather than use rates based on Medicare, which Ross and other rural lawmakers said were unfair and could result in closing hospitals.

Ross and three other fiscally conservative Blue Dogs also extracted cuts to subsidies for middle-income people to buy insurance and a larger exemption for small businesses from a new pay-or-play tax on companies that don’t provide health insurance to their employees in return for voting for the bill in committee.

But with Ross’ recent defection on the public insurance option, that deal now appears to be dead. Liberals had already vowed to oppose a bill that included the deal, arguing that the public insurance option had been weakened too much and that the subsidies for buying health insurance were insufficient.