I think one of the issues with its introduction is how easy it will be to make it appear to be a problem.
Effectively I'd be pretty confident that on the 4th May we will have a lot of people with links to formal or informal protests who will simply pitch up at the polling station without ID and be turned away. This will be all over twitter, other social media and the mainstream media. And people will ask the obvious question - is the solution worse than the problem it was supposed to fix.
Now I'd imagine with a new process all polling stations will need to record the exact number of people turned away due to not having ID - so we will have those numbers, and we already have numbers on ID fraud, based on people turning up legitimately to vote to find they've already 'voted'. We know that number is tiny, so almost certainly the number turned away as they don't have ID will dwarf the number who couldn't vote due to ID fraud.
It really is a solution looking for a problem.