Nigel Farage, who for many Americans was the face of Brexit, has vowed to return to the fight if “sellouts” in parliament continue to stall the nation’s transition away from the European Union.

Unless Brexit is back on track by March 2019, I will seriously consider putting my name forward to return as @UKIP leader. The will of 17.4m voters must be carried out. pic.twitter.com/BNLtA6xPiJ — Nigel Farage (@Nigel_Farage) July 9, 2018

Farage, who was leader of the U.K. Independence Party (UKIP) from 2006-2009 and again from 2010-2016, argued passionately for Britain’s autonomy in the months leading up to the Brexit vote.

On Monday, Farage delivered a statement he termed a “warning to those Tory MPs worried about losing their seats.

“I never wanted a career in politics. I only ever wanted to stop the country I love being sucked further into a political and economic union which is most unnatural to the instincts of the majority of my fellow citizens. However, my own red line is that if Article 50 is suspended or delayed, I will have no choice but to resume campaigning in all parts of the United Kingdom. In March 2019, the current leader of Ukip, Gerard Batten, will reach the end of his term in office. Unless Brexit is back on track by then, I will have to seriously consider putting my name forward to return as Ukip leader.”

He concluded by saying that the failure of parliament to follow through on the obvious wishes of the people was what compelled him to act. “I never thought I would say that again, but the government’s sell-out leaves me with no choice. The latest Brexit betrayal must be reversed.”