Eighty House Republicans collectively sent their party’s leaders a letter Thursday urging them to draft legislation to defund President Obama’s health care reform act, the latest GOP salvo against the administration’s signature legislation.

The letter, sent to House Speaker John Boehner of Ohio and Majority Leader Eric Cantor of Virginia, calls for the House to “continue our efforts to repeal Obamacare in its entirety this year, next year and until we are successful.”

“Obamacare is not ready, and the way it is being implemented is not fair,” said North Carolina Rep. Mark Meadows, who spearheaded the effort. “By choosing to delay the employer mandate, President Obama demonstrated he knows the law is unworkable. If big businesses get a break, hardworking individuals and families deserve the same relief.”

The Republicans, who say most of their constituents are against the law, urged Boehner and Cantor to “defund the implementation and enforcement of Obamacare in any relevant appropriations bills brought to the House floor in the 113th Congress.”

And with the federal government slated to run out of money Oct. 1 unless spending authority is granted to agencies for the new fiscal year, the  letter signers also pressed their leaders to withhold funding for Obamacare-related programs and policies in any emergency spending bills — suggesting they’re willing to shut down the government over the matter.

But a new poll conducted for Republican members of Congress shows significant public opposition — and solid opposition among Republicans — to the idea of shutting down the government over the issue of funding Obamacare.

The survey, done by pollster David Winston, shows that 71 percent of those surveyed opposed a shutdown, while 23 percent favored a shutdown. Among Republicans, 53 percent opposed, versus 37 percent who favored.