By Alex Stevenson Follow @alex__stevenson
Plans to force each voter to register individually are part of a Conservative bid to disenfranchise Labour voters, Harriet Harman has warned.
The Labour party's deputy leader highlighted the bid to "push people off the electoral register" as she wraps up the autumn conference in Liverpool.
"The Lib Dems - to their eternal shame - are colluding with the Tories in changing the law on the electoral register," Ms Harman said.
"What they plan to do in the white paper is going to push people off the electoral register, deny them their voice and deny them their vote."
The Electoral Commission fears this could deny millions of people the opportunity to vote. Many of the country's most underprivileged and hardest to reach could be affected.
"The Tories are doing it because they hope it will help them win the election. that is a shameful assault on people's democratic rights and we will expose it and campaign against it," Ms Harman added.
"If they take away the right to vote from students, young people living in rented flats in our cities, people from ethnic minority communities.
"If fewer of them can vote it will help the Tories win."
Nearly 15% of voters dropped off the electoral register after individual voter registration was introduced in Northern Ireland in 2002.
The government has estimated that 20% of the electorate, around seven million voters, could end up missing if the change is implemented nationwide.
Ed Miliband addressed the issue in his question-and-answer session in Liverpool yesterday evening.
"The government is reassessing the civic duty to register to vote and turning that into a voluntary thing," he said.
"One of the most basic decent rights of all is the right to vote... we should be making it easier, not harder."