Opposition peers are set to join forces in an attempt to block moves to delete nearly 2m names from the electoral register in five weeks’ time.
The Government argues that the planned move from household registration to people adding their names individually will combat electoral fraud.
It has brought forward by a year the date for the switch to the new system, meaning that people who have not re-registered by December 1 will drop off the list.
It said it wanted the new electronic register in place for next year’s Scottish, Welsh and local elections.
But critics claim the move will disenfranchise around 1.9m registered voters, with ethnic minorities, students and people renting their homes among the groups hardest hit.
The Liberal Democrat peer Lord Tyler will lead an attempt to delay the switch to its original date at the end of 2016.
He said: “This is Tory gerrymandering at its worst and a cynical attempt to manipulate the electoral system in their favour.”
The move has also been condemned by Labour leader Jeremy Corbyn, while the Electoral Commission has said ministers acted “without reliable information” and should wait another year.
