Select committees have carried out detailed investigations of extra-governmental conduct before, from bankers to phone hackers to charity executives, with mixed results. Such inquiries are resource-intensive and high risk, with no guarantee of finding an agreed version of events or identifying responsibility for them.

In the BHS inquiry, starting from a position of very limited information the committees demanded known documents, rather than calling for written evidence, and followed the trail to companies and individuals all keen to blame anyone but themselves. These demands, together with the reluctance of some witnesses to attend, raised the question of select committee powers, which remain subject to legal uncertainty (and could be revisited in the new Parliament). However, in the BHS inquiry, existing powers proved largely adequate, not least because the court of public opinion remained on the side of the committees.

The committees were certainly helped by an outraged and absorbed press. The evidence sessions competed with the EU referendum for media coverage, and journalists feasted upon the almost daily publication of contracts, board papers and emails uncovered by the committees. In turn, the high public profile of the inquiry encouraged those with relevant information to come forward, and encouraged journalists to pursue interesting leads and characters in the emerging evidence. Where there is to some degree a confluence of interests, the combination of select committee evidence and findings, on the one hand, and front-page news and strident editorials on the other, can be extremely powerful. Without such pressure – sustained in particular by Frank Field, as Chair of the Work and Pensions Committee, for many months after the committees reported in July 2016 – it is difficult to believe that Sir Philip would have paid as much into the pension fund as he did.

But it is a risky combination too: the press would have been equally ready to criticise any inappropriate use of parliamentary powers and ineffective or grandstanding questioning. Any factual inaccuracies in the committees’ report would have been seized upon by the many highly-rewarded advisers representing the parties involved. In this high-profile case, committee members were aware that they, as well as the witnesses, were to some extent ‘on trial’.

The time commitment required from busy MPs to consume the enormous volume of often technical information needed to perform well in the high-stakes theatre of the evidence session with Sir Philip Green should not be underestimated. Nor should the task of assembling the right support team to advise the committees, analyse the mountains of paper and assemble the report. This level of intensity could not be maintained as ‘business as usual’ for select committees. The committees also benefitted from a sense of shared purpose that such a cross-party group investigating ministerial conduct or a government failure may be unable to achieve.

The collapse of BHS is subject to several ongoing official investigations. Some might argue that House of Commons select committees, with their inherent political considerations, ought not to be conducting complex investigations into private companies and individuals. However, the committees were able to operate with speed, reporting within three months of BHS going into administration; with independence from government; and at minimal additional cost to the public purse. No other body or public inquiry could have achieved this. Select committees have a unique ability to hold to account those in positions of great power and responsibility.

While there is intrinsic value in MPs, as public representatives, asking questions and drawing conclusions about the conduct of bankers, lawyers or retail magnates, ideally such inquiries also yield wider public policy gains. Having reported on BHS, the two committees separately examined the regulatory and legal frameworks surrounding pension schemes and corporate governance. This work was drawn upon explicitly in green papers and in party manifestos for the 2017 general election. It is reasonable to conclude that the committees’ work has resulted not just in a financial settlement for BHS pensioners, but also in an improvement in the reputation of select committees and changes in government policy.