(Politico) — Billionnaire investor Warren Buffet said in a letter Wednesday that he was “delighted” to support legislation to implement the “Buffett Rule,” which would ensure that those making over $1 million annually pay at least a 30 percent effective tax rate.

“I’m delighted to be identified as a supporter of S. 2059,” Buffett wrote in a letter to Sen. Sheldon Whitehouse (D-R.I.), who introduced legislation to implement the rule.

“I have no problem endorsing any large step in the direction of greater fairness in the tax code…Thanks for what you are doing for our country,” Buffett added, according to the senator’s office.

The “Buffett Rule” first entered the national conversation when Buffett pointed out that he pays a lower effective tax rate than his own secretary, and argued that the rich should pay at least the same tax rate as middle-class workers.