*(Via MSN News) – An already heated battle between the White House and Republicans over negotiations to curtail Iran’s nuclear program grew more tense Monday when 47 Republican senators sent a letter to Iran designed to kill any potential deal.

The White House responded by accusing the Republicans of conspiring with Iranian hardliners, who oppose the delicate negotiations, and suggested that their goal was to push the U.S. into a military conflict.

“It’s surprising to me that there are some Republican senators who are seeking to establish a back channel with the hard-liners in Iran to undermine an agreement between Iran and the broader international community,” said White House spokesman Josh Earnest on Monday.

He characterized the Republican effort as a “rush to war or at least a rush to the military option that …is not at all in the best interest of the United States.”

The letter’s main author Sen. Tom Cotton (R-Ark.) described the one-page letter as a remedial civics lesson to help Iran’s mullahs better understand the limits of presidential power.

“Anything not approved by Congress is a mere executive agreement,” the letter states. “The next president could revoke such an executive agreement with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.”

Get MORE of this AP Report at MSN News.