Here's a Canadian perspective.About 2000, we instituted voter ID at the polls.

The reason was that political parties were sending workers to impersonate voters that were unlikely to vote. In a close election (we are FPTP, similar to UK), if one party is perceived to be doing it, than the other party has to do it to "level the playing field."

In our 300 or so constiuencies, maybe 30 had electoral results were close enough where a little cheating would affect the final result. A few seats were won or lost with cheating, but the will of the people was still exhibited in the outcome of the government party selected.

Did we find lots of evidence? Probably not. But the rumors were enough to discredit the entire electoral process.

The first election after the new rules had a lot of people upset. Some were annoyed at having to pull out their driver's license. Some were annoyed that they had to go home and come back. Some didn't come back.

But as federal, provincial, and municipal elections came and went, the voters got used to bringing some ID with them. Voter ID is no longer an issue in Canada.

And we allow utility bills with the voters name and address as valid ID to vote.