The assurance I can give my hon. Friend about this incident is that, throughout the whole process of the investigation as it has unfolded, we have sought expert scientific and public health advice to ensure that people who could have been at risk were not disregarded, whether or not they were in the threatened area. We felt that at Gatwick, for example, there was no threat to his constituents or the people who work there, but we made our decision by seeking the advice of our world experts in places such as the Defence Science and Technology Laboratory and Public Health England.
This also underlines an important point: when a hostile state is determined to try to use its full resources to penetrate another state, the challenge is much greater. The logistical support of that state in assisting its agents is significant. For example, these two individuals travelled on genuine Russian passports, making them harder to spot. There was clearly some attempt to create a legend to ensure that they circumvented our checks. This is only speculative, but at the other end of the aeroplane journey the baggage checks were probably not, I should think, as good as they might have been.