Texas state House Democrats plan to leave to break quorum of a special session in which Republicans aim to pass a new congressional map that could net the GOP five seats.

The revolt by the state House Democrats ratcheted up a widening fight over congressional maps that began in Texas but has drawn in Democratic governors who have floated the possibility of rushing to redraw their own state’s maps in retaliation.

There are 150 members of the Texas House, but 100 — a quorum — are needed to conduct business. The House Democratic Caucus announced Sunday afternoon that the majority of Democratic members would break quorum and leave the state ahead of floor debate scheduled for Monday on a proposed congressional map.