Since the founding of the Labour Party in 1900 as a "broad church", it has seen a steady number of splits and breakaway factions, mainly between the moderate/right-wing and doctrinaire/left-wing sides. Breakway parties are the inverse of entryism, most significantly seen with Militant within Labour, before their expulsion. The most significant breakaway was the Gang of Four forming the SDP in 1981 over economic policy versus the short-lived Gang of Seven forming The Independent Group in 2019 as a protest over Brexit. Both those splits followed the election of a left-wing leader, Michael Foot and Jeremy Corbyn respectively, to the discontent of many right-wing MPs in the Parliamentary Labour Party. Another "catastrophic" split happened in 1931 when Labour was in the National Government. Compared to Labour, the Conservative Party has been "much better at keeping its internal divisions out of the public glare." Some of the breakaway organisations have stayed as independent parties, some have become defunct, while others have merged back with the parent party or other political parties. Generally, the breakways have been too small, split over too few issues, and formed not distinctive enough a party to be sustained.