History. 4 of 7: part refused or the papers ruled short (Brexit sector studies 2017, Brexit legal advice 2018, no-deal plans 2019, Lebedev 2022).
Hunch. On 5 November the Cabinet Office named in advance the grounds for keeping back or redacting the next papers and said any security redactions would go to the Intelligence and Security Committee first.
The shortfall market counts only if new Mandelson papers are laid before the Commons between 5 November and 17 December 2026, and it is void if none are. It resolves YES if by the end of 17 December the government withholds or redacts anything on a ground it had not named for this demand before laying, or if the Intelligence and Security Committee, the Speaker or the Commons says in public that the papers do not meet the demand, not opposition parties alone, or if the Speaker gives precedence to a contempt motion over them, judged on Cabinet Office pages on GOV.UK and committee statements with BBC News and The Guardian as backup.
We looked for cases where the Commons passed a demand from MPs outside the government for government papers, and checked the first papers that came back. We found seven such demands from 2017 to 2026. Four came from 2017 to 2019 and were about Brexit, and only the 2026 demand ran alongside a police investigation.