We don’t know what will be in the Investigatory Powers Bill – which will be published on Wednesday – but we do know what will happen to it, at least initially.  Since it will be a draft bill, it will be scrutinised by a Joint Committee of MPs and peers before beginning its journey through Parliament.  One of the main objectives of joint committees is to smooth out tangles in Government legislation before it is presented to the Commons or the Lords.  I served on one when I was in the former; it examined a draft Disability Discrimination Bill.

These draft committees are especially useful if the Bill in question can be improved early by expertise and is controversial.  The disability bill fell into the first category.  The surveillance bill will fall into both.  It will be hard to find peers, and perhaps especially hard to find MPs, who have both at least nodding acquaintance with the world of the security services plus a grasp of how today’s technology works.  On the Conservative side, there is obviously my old mucker David Davis, but his relationship with the Government is very spiky indeed.

Other senior MPs with a civil libertarian bent are Dominic Grieve, but he is busy chairing the Intelligence and Security Committee, and Andrew Tyrie – also also otherwise engaged, this time chairing the Treasury Select Committee.  Some in the security services and police will object that having Parliamentarians with this disposition on the bill committee would risk distorting its findings.  Quite so, if it only consisted of those opposed to the services having all the powers they want.  But having some of them on the committee would help to get the Bill into a shape in which Parliament is more likely to pass it.

At any rate, there is a suitable chairman to hand.  Lord Blencathra, formerly known as David Maclean, chaired the joint committee that reported on the Draft Communications Data Bill in 2012.  Blencathra is a Conservative ex-Commons Chief Whip and a former Home Office Minister.  So he understands something of the culture and needs of the department and the services.  But his committee, while supportive of that Bill in principle, was critical of some of its original proposals.  The first big test for this new committee will be who chairs it.  Blencathra’s appointment would pass that test with flying colours.