Senate Republicans cannot force the U.S. Postal Service to scrap thousands of electric vehicles and charging equipment in a massive tax and budget bill, the Senate parliamentarian said late on Sunday.

The U.S. Postal Service currently has 7,200 electric vehicles, made up of Ford e-Transit vehicles and specially built Next Generation Delivery Vehicles built by Oshkosh Defense.

USPS warned on June 13 that scrapping the electric vehicles would cost it $1.5 billion, including $1 billion to replace its current fleet of EVs and $500 million in EV infrastructure rendered useless and “seriously cripple our ability to replace an aging and obsolete delivery fleet.”

Senate parliamentarian Elizabeth MacDonough, whose role is to ensure lawmakers follow proper legislative procedure, said a provision to force the sale could not be approved via a simple majority vote in the Republican-controlled chamber and will instead need a 60-vote supermajority, according to Democrats on the Senate Budget Committee.