President Obama would veto any legislation aimed at unraveling his executive action on immigration even if it means shutting down the government, White House spokesman Josh Earnest said Monday.

Earnest predicted Obama would use his veto pen to reject any measure taking aim at his action providing relief for more than 4 million illegal immigrants, but cautioned that he didn’t believe Republicans would craft a bill in such a way that it would lead to a government shutdown if he refused to sign it into law.