Outgoing Rep. Dennis Kucinich (D-Ohio) said Tuesday that the Keystone XL pipeline approval mandate that is currently being debated by a conference committee on a proposed multi-year surface transportation bill will lead to higher prices if it becomes law.

Kucinich, who was ousted in a primary in March by Rep. Marcy Kaptur (D-Ohio), said a study released by the Natural Resources Defense Council showed the Keystone approval would increase the amount the U.S. has to spend on gasoline by $4 billion by “limiting the supply of Canadian crude to Midwest refineries and rerouting it to Gulf Coast refineries.