Cities that have passed policies deeming themselves “sanctuary cities” for illegal immigrants may be finding themselves staring at a loss of federal infrastructure funding if a House Republican’s bill becomes law.

Missouri Rep. Jason Smith wants to block any sanctuary city from receiving money from the Federal Highway Trust Fund, one of the biggest sources of funding for improvements to roadways across the country. The bill, the No Transportation Funds For Sanctuary Cities Act, would be the legislative culmination of Republican threats to end sanctuary city policies across the country.