History. No count from the six: two had no document by 31 January, and in two the promise itself said white paper or green paper, so the form was set from the start. In the other two, Johnson's 2021 social care plan and his 2020 green plan, the main measures stood in the document.
Hunch. On 5 November Andy Burnham rejected the report of a thin plan and said his plan will be substantial.
The measures market counts only if the plan is published by the end of 31 January 2027, and it is void if it is not. It resolves YES if GOV.UK presents the document as a consultation, or the document opens a public consultation on the plan's content or priorities, or leaves the main measures of the plan as a whole to a later named document, and NO in every other case, including a high-level document that names no later document; parts of a policy area, or money left to the Spending Review, do not count, judged on the document with BBC News and The Guardian as backup.
We looked for cases where a UK prime minister promised a major government document and said it would come by the end of the year. We found six, from 2012 to 2021. Three came out in time. In the other three nothing was out by 31 December.