There are plenty of Boris Johnson hangovers to give Rishi Sunak a headache these days. The privileges committee investigation into whether the former prime minister misled parliament will soon be in full swing. This doesn’t just mean that ‘partygate’ will be back in the news. If the committee finds Johnson guilty then Sunak could face the unappetising prospect of deciding whether to whip his party to vote either way in relation to any recommended punishment (such as a suspension) and what to do himself.