Bernie Sanders is blasting what he calls “the corporate wing of the Democratic Party,” as centrists are reportedly growing more comfortable with Elizabeth Warren and the Massachusetts senator leads her Vermont counterpart in at least one presidential poll.

Linking to a Politico story titled “Warren emerges as potential compromise nominee,” Sanders tweeted, “The cat is out of the bag. The corporate wing of the Democratic Party is publicly ‘anybody but Bernie.’” Sanders said his agenda including Medicare for All and breaking up big banks “is the real threat to the billionaire class.”