Johnson and Starmer trapped by the Plague Index

Labour and the Conservatives head for their annual conferences with Britain’s voters in much the same mood as Romeo’s wounded friend, Mercutio: “a plague on both your houses”. The voting intention figures tell only a fraction of the story; we shall come to these later. The larger truth is that, unusually, the leaders of the two main parties are both unpopular.

Two months ago I discussed the weak reputations of Labour and the Tories. With the centrepiece of the coming conferences the set speeches of the leaders, their personal ratings deserve special scrutiny.

For almost seventy years pollsters have been asking people whether they are satisfied or dissatisfied with the Prime Minister and Leader of the Opposition. In the Fifties and Sixties it was not uncommon for both to command public respect. In July 1961, to take a month not quite at random, 54 per cent were satisfied with Harold Macmillan’s performance as Prime Minister, while 33 per cent were dissatisfied: a net score of plus 21. His Labour opponent, Hugh Gaitskell, also enjoyed a net score of plus 21, with 51 per cent satisfied and 30 per cent dissatisfied. Add those two net scores together and we have a combined net rating of plus 42.

These days, we seldom see such strong scores for both leaders simultaneously. A brief exception occurred in April last year, days after Boris Johnson had been in hospital with Covid, and Keir Starmer had been elected as Labour’s leader. For some decades it has been more normal for one of the two party leaders to be up and the other down. Only rarely have both been unpopular together. The exceptions stand out: Harold Wilson and Edward Heath in 1968, Margaret Thatcher and Michael Foot in 1981, David Cameron and Ed Miliband in 2012/13, Theresa May and Jeremy Corbyn in 2018/19.

Those exceptional times are back. To show what has happened and put this analysis on a more systematic basis, we can combine the net scores of both leaders to construct a “plague index”. When both are well in negative territory for more than a few weeks, the electorate’s verdict is, indeed, a plague on both your houses. That is where we are now, and the story of the 18 months in which Keir Starmer and Boris Johnson have faced each other across the despatch box is instructive.

In the early weeks of the pandemic, Opinium’s fortnightly polls for the Observer recorded positive scores for both leaders. Starmer stayed popular for the rest of the year: his net score – the percentage satisfied minus those dissatisfied – averaged almost plus 20. In contrast, Johnson struggled. As Covid spread and the lockdown continued, his net score went negative and stayed there, reaching its worse level, minus 14, in late October and early November, during the second lockdown.

The following table shows what has happened this year, according to Opinium’s monthly averages:

The first three months of the year conformed to the normal historic pattern, with the two leaders in opposite positions and heading in opposition direction: Johnson recovering from a weak rating and climbing as the vaccine programme gathered pace, while Starmer slipped back from a strong positive score. By combining both, the Plague Index stayed close to zero.

That changed as we headed through spring to the summer. Both leaders’ ratings fell: Starmer more abruptly, Johnson more gradually. For the past four months, both men have had negative scores and the Index has descended to around minus 20: well into plague territory.

It would be going too far to describe the present state of affairs as a crisis of legitimacy. The numbers would have to be much worse for much longer for that. However, they do contain a warning. This month’s announcement of tax rises to pay for the NHS and social care is just the first of many tough decisions that will be needed in the current decade. The pressures on our leaders will only grow: on the cost of public services, the need over time to repair government finances, paying for the changes to tackle climate change – not to mention repairing the economic damage done by Brexit.

In difficult times it helps if at least one of the party leaders, and preferably both, commands public respect. If neither does, then the task of persuading voters to accept tough measures becomes harder – especially when both men, struggling to revive their fortunes, snarl so angrily at each other. If Tesco and Sainsbury were to devote their marketing budget to accusing the other of selling their customers short, we should not be surprised if shoppers concluded that both were useless.

Meanwhile the latest voting intentions suggest that the Tories have regained a modest lead over Labour. On the basis of its private polls, the Government had hoped that voters would back the recent tax rises for the NHS and social care. In the event those hopes were dashed. (Moral: be wary of polls that ask hypothetical questions.) The Tories have now regained some of the ground they lost, but not all of it.

However, the real lesson from the Plague Index is that support for both parties is fragile. If it stays strongly negative, and especially if it gets even worse, opportunities will open up for other parties, such as the Liberal Democrats and Greens; and the SNP will be hard to dislodge in Scotland. On the other hand, both Labour and Conservative have the chance to break out of their current near-deadlock in voting intention and if either Starmer or Johnson can revive their personal fortunes.

The party conferences in the next fortnight might give us some clues as to whether either leader will heed the warnings from the Plague Index and begin the process of recovery.

This analysis was first published by Prospect