Let those who are never divisive cast the first stone.
In some senses all democratic party politics are divisive, as parties seek to differentiate their policies and achievements from the others. The Church of England can also be divisive, when it decides to intervene in party political debates.
The 1970s were no haven from divisions. I seem to remember the punitive tax and spend policies which forced us to borrow money from the IMF, and forced large public spending cuts on us as a result, were very divisive. So too was the winter of discontent, when the Trade Union movements turned against the wider public and against the Labour government.
The noughties were also divisive. The Iraq war was bitterly opposed by many. The boom and bust policies were oopposed by a few of us in the boom phase, but by many when so many suffered from them in the bust phase. Bankers were then made the scapegoats for a wider failure of the government, Central Bank and regulators as well as of the bankers.