I thank the hon. Member for Oxford East for her observations, particularly the curious incident of the dead dog and the bike, which I think might end up being one of the most memorable statements in the passage of the Bill.

The hon. Lady eloquently alluded to the impact of such measures on the size or type of vehicles used to carry out the business activities that we are discussing. I point to my earlier remark that, if a fixed rate per mile can be claimed, there is an incentive to use a less expensive means of transport, be it a bicycle or a less polluting vehicle, while claiming the mileage. A useful dynamic, in terms of her interest in this area, is built into the system.

As I have pointed out, the measure is a simplification, not a tax reduction. That is a pertinent point when it comes to a review of behavioural change, because it does not change the overall weight of the tax burden on this group. As I have set out, the Office for Budget Responsibility has stated that the fiscal impact of the measure will be negligible—meaning that the impact will not exceed £5 million in any year—in every year of the scorecard period, albeit that 1.8 million businesses are affected by it.

The hon. Lady asked how we will know if people are abusing the system by claiming mileage allowances for a use other than business use, or for travel that has not occurred. That problem is implicit in any arrangement of this nature, in which expenses are claimed as a tax deduction. HMRC has become more and more sophisticated in how it looks at tax returns—that is clearly how such information would be provided—and it uses technology to look for patterns and abnormalities. It sometimes looks at whole subsets of taxpayers that have a greater propensity to do certain things, and it therefore investigates members of those groups more rigorously. That would be part of the approach.

Overall, I do not think it is necessary to have a review, particularly given the negligible impact of the change. On the grounds of proportionality, I ask the hon. Lady to consider withdrawing the new clause.