A public health association and one of the nation’s largest worker unions are suing the Trump administration over the abrupt cancellation of hundreds of research grants, arguing that the moves were arbitrary and capricious and that the federal grant process is supposed to be above politics.

A group of scientists and health groups sued the National Institutes of Health on Wednesday, arguing that an “ideological purge” of research funding is illegal and threatens medical cures. Since President Donald Trump took office in January,