Electoral Commission says it cannot show how different areas have been affected by switch to individual registration
Software problems have left the Electoral Commission unable to spot the areas worst hit by the switch to Individual Electoral Registration (IER), the watchdog has revealed.
The Commission has said it is "highly unlikely" to recommend adopting the voting rolls collected through IER this year, as ministers have hoped.
Now it has set out its reasons for the stance in evidence to a parliamentary inquiry, explaining the data gaps which mean it cannot give a "completely up to date picture on the transition".
Jenny Watson, the Commission's chairwoman, said town halls no longer had problems identifying people who had been 'matched' from existing databases, an earlier hiccup.
Instead, she said: "There should be an ability to press a button and get an automatic report generated that would tell us, for example, how many electors in each local authority area would be lost to the register if the transition arrangements were not in place.
"That is the kind of data that we do not have, which means that we cannot give the perspective on the transition at a local level that we would have wanted to give.
"It is not affecting in any way the service that voters receive - it is affecting our ability to give you a completely up to date picture on the transition.
"Unless the suppliers and the Cabinet Office can get that right, we would not be able to recommend bringing the date of the transition forward - because we would not have the data quality to be able to do that."
Half of data
Phil Thompson, the Commission's research manager, added: "I think we only have reportable data from 158 electoral registration officers across the country. That is just less than half.
"What it doesn't let us say is what the variation is between the 158 people who have reported to us.
"Some people have virtually no electors on their register who are being retained under those transitional arrangements, and there are other areas where it is a fifth."
The Commission's report, due in June, will determine whether the IER rolls will be adopted from December this year, or not until December 2016.
Last year, it announced that data matching had successfully verified the details of 87% of current electors who had been transferred automatically to the new IER registers. The details of 5.5m existing electors - or 13% of the total - had not been matched or transferred, but they can vote from the old household registers in May's general election.
The Commission explained the data gaps in evidence to the Commons political and constitutional reform select committee, last month. A transcript has been released.
Pictured: Polling Station in Haverhill 2007 by 159753 (Own work) [Public domain], via Wikimedia Commons