The future of the speaker of the US House of Representatives has been thrown into serious doubt after the chamber voted to move ahead with an effort by hard-right Republican critics to oust him.

The narrow outcome forced by Kevin McCarthy’s chief rival, Matt Gaetz, brought together a handful of conservative Republican critics of the speaker and many Democrats who say he is unworthy of leadership.

The vote was 208-218 not to table the motion, with 11 Republicans allowing it to advance.

By refusing to set aside the motion, the House opens an extraordinary floor debate ahead of the next round of voting.

It is a stunning moment for the embattled Mr McCarthy which serves as the most severe challenge yet, a potential punishment sparked by his weekend decision to work with Democrats to keep the federal government open rather than risk a shutdown.

The California representative insists he will not cut a deal with Democrats to remain in power.