Monday morning’s resignations by seven Labour MPs are a mistake, but they are also a warning. Like it or not, and a few on all wings have always disliked it, the Labour party is not a centralist party. It has always contained, and has been able to contain, a mix of political traditions. Most fundamentally of all, it has long been a coalition of organised labour and various mainstream socialist and social democratic traditions. Arguments have often been fierce, but they have mostly taken place within a large tent. After nearly 120 years of the party’s history, that is still, for the moment, the case.

At various times in this progress the party has tacked more decisively in one direction or another, putting that mix under pressure. Over the last century, Britain has also changed in fundamental ways that challenge the party – any party – to adapt or perish. Yet, by and large, Labour activists, interests and voters have managed to remain, if not united, then at least broadly agreed on a common purpose. That purpose is, overwhelmingly, the election of Labour governments that can redress the imbalance of economic, social and political power in Britain. That broad-church approach has served Labour well and has served Britain well too.

The Labour MPs’ decision to resign from the party needs to be seen in that context. If nothing else, it is very clearly a warning sign that the party is in the midst of one of its periodic tacks, to the Corbynite left in this case, which put the broader, long-term coalition of Labour at some risk. Such breaches are not new. But this one is now a fact. It needs to be taken humbly by all those who remain committed to the Labour cause and who believe, especially in the context of Brexit and the capture of the Conservative party by the nationalist right, that Britain badly needs an effective Labour government.

Nevertheless, the most striking facts about the resignations is that they were so low-key and that there were so few of them. It is no secret that many, perhaps most, Labour MPs wish someone other than Jeremy Corbyn was leader. Many Labour MPs wish that Mr Corbyn would make the case for Britain in Europe, and that he did not equivocate about antisemitism in the party. Yet there is no evidence that the majorities who voted for Mr Corbyn in 2015 and 2016 – or the trade unions – have wavered in their support. Even after Monday’s resignations, this is not a party in the kind of civil war that convulsed Labour under Michael Foot in 1981. That may happen in the future, but the fact that it is not happening now suggests that Mr Corbyn’s critics mostly intend to stay and argue their case.

As long as that uneasy stand-off remains, and the divisions are not pushed to a flashpoint, there is little appetite for all-out Labour conflict. The resignations seem to mark individual moments of accumulated personal despair rather than a moment of collective political defiance of the sort that Roy Jenkins and the “gang of four” produced nearly 40 years ago. There were no moves on Monday to launch a new party or even to set out a new programme. So, while they may be understandable, these resignations are regrettable. They should not be followed but they should not be exploited to trigger a party purge either. The case for a broad-church Labour party – one that embraces all of its traditions as legitimate – remains compelling, even in such difficult times, and especially in the face of the national tragedy over Brexit. Mr Corbyn could do far more to reinvigorate such a conception of Labour than he does. These resignations are a signal to him that he should do so.