(CNN) – Rep. Ed Markey, running in a special election for U.S. Senate in Massachusetts, is highlighting his response to 2010's gulf oil spill in a new ad released Thursday.
The longtime Democratic lawmaker led the charge to put a live stream of the leaking wellhead online, and pushed for legal action against BP, the owner of the oil platform where the leak began.
"Eleven dead. Communities ruined. The worst environmental disaster in American history. When BP tried to avoid responsibility, one man said no," a narrator says in the spot.
"Ed Markey uncovered the extent of the damage, and when BP executives lied, Ed Markey held them responsible," he continues.
Markey will face fellow Democratic Rep. Stephen Lynch in a primary contest April 30. The special election is slated for June. The winner will fill the seat formerly held by John Kerry, who stepped down to become secretary of state.
Last week, major progressive groups MoveOn and Democracy for America endorsed Markey in the primary.