Former Bank of England policy maker David Blanchflower said a letter to Federal Reserve Chairman Ben S. Bernanke urging him to halt an expansion of monetary stimulus is “dangerous politics” and displays “very little understanding” of the economy.

The letter-writers are “playing with an economy that’s fragile,” Blanchflower, a professor at Dartmouth College, said in an interview with Bloomberg Television today. “Thank goodness” the Fed hasn’t “listened to these folks who would drive us back into recession and probably a depression.”

A group including former Republican government officials and economists urged Bernanke in a letter to stop his expansion of monetary easing, saying it risks an inflation surge.

The missive will be published in tomorrow’s editions of the Wall Street Journal and New York Times, said Jennifer Pollom, a spokeswoman for Economics 21, a Washington research group whose logo is on the letterhead.

“These folks are advocating cutting fiscal spending at a time when you should be adding stimulus,” said Blanchflower, a Bloomberg News columnist. “The Fed has to compensate for what these folks advocate.”

The central bank “is the only show in town,” he said.