How fast is Theresa May losing ministers?

3 departures in six months is high, but not ridiculous.

Earlier this week, Damian Green resigned as Minister for the Cabinet Office.

Last month, both Priti Patel and Michael Fallon resigned within a week of each other.

Is three ministerial departures a lot, or a little?

To find out, I turned to data made available by Katsunori Seki and Laron K. Williams. Their update to the Party Government data-set provides information on governments and ministers from 1990 until 2014. It lists the start and end dates of each government, and start and end dates for each ministerial spell. It is the most comprehensive source of data on ministerial tenure I can find.

Using this data, we can calculate a running tally of the number of exits from government, for each government.

By an exit from government, I mean any time that a minister ceased to be in government at all. I'm not including reshuffles. If a minister ceased to hold a given portfolio, but took on a new portfolio within a week, I don't count that as an exit.

Here are the running counts of exits from government for the 328 governments featured in the data-set. Each line represents a government: the line ends with the last ministerial exit prior to the government ending.

You'll see that the May government (highlighted in red) is far from the quickest at shedding ministers. If the May cabinet were to end now, it would be in the top fifth of cabinets for the rate at which it has lost ministers. Yet other governments have ended up losing more ministers, more quickly. I've highlighted these in the figure. Three of the worst performers come from Japan during the nineties, a rather messy period in the country's politics, when the LDP was not as dominant as it once was (and would subsequently be again).

If we compare the May cabinet to those British cabinets for which Seki and Williams provide data, we can see that the May cabinet is unusual.

Some of these comparisons may be inappropriate. Some ministers' exits from government are freely chosen by the prime minister, whilst others are forced upon her. As my colleague Nick Allen has already noted, a good quick purge of the front bench can even signal a strong prime minister. In many of these recent ministerial resignations, it seems as though the prime minister has more often found herself in zugzwang.

Note: you can find the (slightly messy) code used in this analysis at GitHub.