Democratic Sens. Charles SchumerCharles (Chuck) Ellis SchumerAmtrak to rename Rochester station after Louise Slaughter Conscience protections for health-care providers should be standard Pension committee must deliver on retirement promise MORE (N.Y.) and Bob CaseyRobert (Bob) Patrick CaseyHouse GOP frets over Pennsylvania race Do the numbers add up for Democrat Conor Lamb in Pennsylvania? Poll: Five Senate Dems would lose to GOP challenger if elections held today MORE Jr. (Pa.) on Thursday will unveil a plan designed to punish people who renounce their citizenship in order to dodge U.S. taxes. The plan is a direct response to Eduardo Saverin, the wealthy co-founder of social networking site Facebook.

Schumer and Casey allege that Saverin is looking to avoid millions in U.S. taxes by giving up his citizenship a few months before his company goes public. Saverin's stake in the company is expected to be worth more than $3 billion as of Friday.

In a press release, Schumer and Casey called Saverin's move an "avoidance scheme." The plan they will introduce later on Thursday specifically takes aim at individuals like Saverin who "flee" the country and become residents of another, taking measures to re-impose taxes on expatriates and bar them from re-entering the country.

Schumer and Casey charge that Saverin is looking to save up to $67 million in taxes by renouncing his citizenship. The amount was calculated by Bloomberg as Saverin's initial capital gains bill, but denied by Saverin's spokesman.

Saverin, a dual citizen of Brazil, requested to give up his U.S. citizenship in September, according to IRS documents.

Saverin has denied that he is giving up his citizenship in order to dodge U.S. taxes. He currently lives in Singapore, a country that taxes income but not capital gains.

"This had nothing to do with taxes. I was born in Brazil; I was an American citizen for about 10 years. I thought of myself as a global citizen," he told The New York Times in an interview published Wednesday.

According to the Times, Saverin could be saving himself around $100 million by renouncing his citizenship before cashing in his Facebook shares after the company's initial public offering.