Democratic presidential hopeful Elizabeth Warren is proposing a new tax as part of her plan to “end lobbying as we know it.”

The Massachusetts senator on Wednesday outlined what she called an “excessive lobbying tax,” under which companies that spend between $500,000 and $1 million a year on lobbying would pay a 35% tax on those expenditures. For spending above $1 million, the rate would increase to 60%, and for lobbying outlays of more than $5 million, the rate would go to 75%.