Prison Officers Mr. Tom Cox asked the Secretary of State for the Home Department if he will estimate the number of extra prison officers needed to be able to reduce to zero the average 16 hours overtime worked at present per week by prison officers. Mr. Mellor A straight mathematical calculation is not possible since it would have to take account not only of the effectiveness or otherwise of the working arrangements in force but also of the work at present not done in establishments. Under the group working arrangements in the Department's fresh start proposals, we envisage being able to maintain and even extend existing regimes for prisoners with existing numbers of staff working a substantially reduced average working week, with the prospect of further efficiency improvements once the new systems are in place.