ithink you are confussing local and general elections the local elections coming up in may should be decided on local issues though it could give the pm a headache if people choose to use it as a vote of no confidence in the goverment however it wont remove him from power.
A general election is the one to change the government however looking at recent opinion polls i cant see that happening any time soon
"Can anyone else remember when the political parties used to actually take older and infirm people to the polls?"
Yes, and local well-known worthies got similar treatment. A local clergyman once told me that the Tories had offered him a lift to the polling station. "But I'm a Labour voter" he said. Doesn't matter" they replied. "Just go in our car."