maybe, but probably more to do with the sheer complexity involved. Voting is on a ward or constituency basis which would mean producing a list of candidates for every locality, plus ensuring that the elector had the right to vote there.
You can register on-line for a postal vote but the ballot paper will be sent by post which you can return either by post or taking it to your local polling station. You cannot actually cast a vote on-line.
I miss having the crawling bastads knocking at the door every time there`s an election on, I used to tell them they`ve got 2 minutes to convince me to vote for them and then shut the door after 30 seconds