Moody Bible Institute, one of the bastions of American evangelicalism, has clamped down on a perceived theological drift among its staff, demanding they sign an ultra-conservative statement of faith on biblical inerrancy.

The Chicago Statement on Biblical Inerrancy is seen in many quarters as the benchmark of conservative evangelicalism.

In an email to staff and alumni the Institute announced signing the Chicago Statement would be a condition of employment at the beginning of the 2018-2019 academic year, according to Julie Roys, a long-time Moody Radio host fired for exposing allegations of financial misdealing on her blog.

Roys, a conservative commentator who has warned against 'theological drift', reported last month that two Moody professors affirmed Moody's doctrinal statement but rejected the Chicago Statement.

Created in 1978, the statement was written by leading evangelicals such as JI Packer, RC Sproul and Norman Geisler, and signed by nearly 300 evangelical scholars.

The decision by Moody Bible Institute, founded in 1886 and named after the renowned American evangelist Dwight L Moody, comes after a period of intense criticism over its financial conduct.

Requiring staff to sign the Chicago Statement is seen as the MBI tightening its definition of unacceptable theological views.