MICHELLE O'Neill has called for a meeting with Secretary of State Brandon Lewis over plans to update the electoral register.
Chief electoral officer Virginia McVea has said she plans to press ahead with the review, which is a legal requirement, but has stressed that it will not involve staff calling door-to-door and would not compromise public health guidelines.
The canvassing exercise was delayed last year due to the Covid pandemic.
Sinn Féin has voiced concerns about the review, with Ms O'Neill claiming it will "wipe the existing electoral register" and could lead to "tens of thousands of people losing their vote".
"The Electoral Office should be looking at new and innovative ways of making it easier for people to register and to vote instead of making it harder," the Sinn Féin deputy leader said, adding that she had written to Mr Lewis calling for an urgent meeting to discuss the matter.
