The rules are as follows:
607.The whole of an Assembly constituency must be contained in the same electoral region. It must not straddle two or more regions.
608.The electoral regions must contain a similar number of electors, so far as is reasonably practicable. There may be special geographical factors which mean that this is not reasonably practicable, and these can be taken into account.
609.The number of regional seats must be half the number of Assembly constituencies. For example, if there are 40 constituencies, there must be 20 regional seats.
610.However, if the number of constituencies can’t be divided exactly by 2 (e.g. 39), one is added to the number of constituency seats, and then that number is divided by 2.
611.For example, if there were 39 constituencies, “1” would be added to 39, to give 40, and 40 would then be divided by 2 - so the number of regional seats would be 20.
612.The number of seats in each electoral region will be the total number of regional seats in the Assembly, divided by 5. Therefore, if the total number of regional seats is 20, the number of regional seats in Assembly electoral region “A” will be 4.