The Investigatory Powers Bill was passed by the Commons with a considerable majority - but a number of issues are in play. The biggest is that David Anderson QC's review of the operational case for the proposed bulk data-gathering powers is due to emerge before detailed committee stage scrutiny begins, and his recommendations could force the government to concede some major changes.

Ministers have also promised to bring forward amendments on a variety of issues - and there is likely to be further debate on the issue of keeping internet connection records and the level of access to them.

The Liberal Democrats, with a phalanx of 108 peers, are pledged to try to strike down what they regard as the most intrusive parts of the bill - but it is worth noting that Labour backed it at third reading in the Commons, and that the ranks of Labour peers include some pretty hard line former home secretaries, which suggests they will need some pretty serious provocation to attempt to defeat the government - and as ever the mathematics of the House of Lords makes a government defeat next to impossible, if the official opposition does not come out to play.