That is a very good point. We have all sorts of debates in this place on blacklisting recently; it is a problem that goes back many decades and persists in many sectors today.
My next question for the Minister is whether there has been any assessment specifically of the effect of the future legislation on the sectors of the economy that are particularly casualised. I am thinking of construction, agriculture, hospitality and catering. In construction and agriculture, particularly, the fluid nature of the work force means that it is difficult to keep accurate records of membership.
I have worked for three trade unions in the past and trade unions, more now than at any time in their history, devote enormous resources—as many as they possibly can—to organising records and keeping them up to date. As I said when I intervened on the hon. Member for Stevenage (Stephen McPartland), large general unions, particularly Unite and the GMB, can easily lose 12% of their membership, particularly at a time such as this. Their membership tends to stand still because they can recruit another 12% in the same sectors to take the place of those members who have been lost because of jobs being lost, factory closures and so on, but just to stand still they have to recruit 12%. The level of churn means that it is difficult to keep records up to date, no matter how many resources are devoted to record keeping. Of course, up-to-date records are dependent on members informing the union that they have moved house, for instance, or changed occupation. That does not always happen.