It appears that a number of BCS members who have now had chance to see both sides of the debate wish to change their vote.
The Electroral Reform Society, the independent body running the voting on behalf of BCS, have therefore provided he following information.
"Should someone wish to alter their vote, they should notify us by emailing firstname.lastname@example.org. We will be able to reset a person’s security codes and they will then be able to login again and resubmit their proxy form. Similarly, we can also re-issue a paper ballot and remove the original from the count."