AMID the kerfuffle over the rejection of tax-credit reform by the House of Lords, another statutory instrument slipped through the chamber on October 27th, by just 11 votes. The motion was a seemingly humdrum bit of administration, swapping the responsibility for signing up to vote from households to individuals. Westminster’s unelected members may have been picking their battles. But timing is important, and some now fear that damage to Britain’s democracy may be on the horizon.

According to the Electoral Reform Society, a campaigning organisation, the forthcoming switchover will be the biggest change in electoral registration since women got the vote, and generally a good thing. Today’s system is a relic of a time when democracy applied only to property owners, can sometimes be prone to voter fraud, and occasionally puts people on the ballot twice. Almost everyone agrees that it is time for a change.

The trouble comes in getting there. Although the government has already used paper records to move about 90% of people from one system to the other, officials must harass everyone else to re-register. In June the Electoral Commission, the official election watchdog, announced that some 1.9m people had fallen through the cracks. They are made up mostly of students (until last year universities could block-register student halls), people in big cities, and those who move frequently or live many to a house. In other words, they tend to be Labour voters. In Hackney, an inner-London borough, 23% of voters were lost around the time of the 2015 general election, compared with an average of 3.5% in south-east England.

The changeover was due to happen in December 2016: time enough for Labour to bombard its electorate with letters, e-mails and unexpected visits. But the Conservative government has decided to bring the plan forward by a year—the old list will now be wiped this December—in the kind of rushed job, the Electoral Reform Society has warned, that could be “hugely damaging to our democracy”. The Electoral Commission, unusually, expressed its “disappointment” at the decision.

Labour is furious. Unless the missing 1.9m sign up sharpish it could face a disadvantage in several important elections due to take place next year: those of London’s mayor, the Scottish Parliament and the Welsh National Assembly, as well as various elections of local police commissioners. And if the lost voters never get the memo, it will also hamper the party in elections to come.

Labour has another worry: a forthcoming constituency-boundary review. As part of a change that will see the number of MPs reduced from 650 to 600, constituency maps are due to be redrawn in order to make them fairer (at the moment they are thought to advantage Labour, though there is some debate about this). But the change will be based on a snapshot of the voting register in December, after the old electoral roll has been binned. The new boundaries will leave out those who have failed to sign up by that point, leaving them under-represented in Parliament.

It will be hard for the Tories to wriggle out of accusations that the move is rather ruthless. John Penrose, the minister for constitutional reform, has argued that it is important to eliminate fraud before boundary lines are redrawn. Yet research by the Electoral Commission has found that fraud tends to be limited and localised, and that it is rooted out fairly smartly. A study of polling stations by the University of East Anglia found that only around 1% of poll workers had concerns about voter fraud, but that two-thirds of polling stations had turned away at least one voter who was not registered. In other words, missing real voters off the list seems to be a bigger problem than bogus ones slipping on to it.

The rushed-through changes will win the Tories few fans, but the next general election is still five years away, and those who are angriest about the changes may find they cannot express their frustration at the ballot box. Labour must find its missing voters before it is too late.