Sen. Bernie Sanders (I-Vt.) on Monday released a plan that would eliminate some of the last unrestrained corporate spending in Democratic politics, by banning corporate funding for the partys nominating convention and presidential inauguration events.

Sanders proposal to get corporate money out of politics the first plan his presidential campaign has released since he was hospitalized for a heart attack last week would, among other things, ensure public financing of federal elections, create a new federal elections oversight board, prohibit advertising during presidential primary debates, and enact a lifetime lobbying ban for former members of Congress and top staffers.

But replacing corporations sponsorship of the Democratic National Convention with a public financing system is both the most ambitious and the most controversial element of Sanders proposal. Seventeen donors were responsible for contributing three-quarters of the funding for the partys 2016 convention in Philadelphia, including a $5.6 million in-kind donation from Comcast for broadcast and internet services.

Sanders said his own campaigns success raising money in small increments he topped the Democratic presidential field with a $25.3 million haul in the third quarter of this year shows that corporate money and wealthy donors are not necessary.

Our grassroots-funded campaign is proving every single day that you dont need billionaires and private fundraisers to run for president, Sanders said in a statement accompanying the plan. When we win the Democratic nomination and defeat Donald Trump , we will transform our political system by rejecting the influence of big corporate money.