Voters in Jeremy Corbyn's north London constituency have accused the Boundary Commission of "gerrymandering" over plans to abolish the seat as part of a move to reduce the House of Commons from 650 to 600 MPs.
Islington North is one of 50 constituencies due to disappear under proposals published by the Boundary Commission for England (BCE) last year, with Mr Corbyn pitted against two of his closest lieutenants - Diane Abbott and Emily Thornberry - in the race for selection as candidates for two new seats which will replace the three they currently hold.
Mr Corbyn himself has said he is "very unhappy" at the proposed change, and new documents released by the BCE show that some loyal constituents have protested on his behalf.
The BCE released almost 20,000 responses to the first round of its consultations on the changes, due to take effect in time for the 2020 general election. Voters now have until March 27 to take part in a second round of consultations, with final proposals due in October 2018.
One Islington North respondent denounced the changes as "nothing short of gerrymandering" designed to remove "a stalwart voice of justice, equality and honesty". And another said there was "blatant gerrymandering going on here to split up a safe Labour seat which is represented by the leader of the opposition".
Another wrote: "I'm suspicious that all this boundary-moving is a ploy to make it difficult for Corbyn to remain leader of the opposition, by preventing the group of people who voted him in as their MP from being able to do this again."
Another response read: "I think the boundary review is disgraceful. I love my MP (Emily Thornberry) and I have huge admiration for the MP of Islington North (Jeremy Corbyn). I dread the idea of merging these two constituencies together and getting rid of one of them."
The BCE has been asked to make independent recommendations on changing constituencies to ensure that each has roughly equal numbers of electors.
Responses to the first round of consultation can be seen at www.bce2018.org.uk where voters can highlight issues and support counter-proposals until March 27.
BCE secretary Sam Hartley said: "Public input is invaluable throughout the 2018 Boundary Review. Comments made during both consultations will help us develop a well-rounded picture of how local communities live and work together across the country.
"This local knowledge will be essential when we revise our proposals. Any changes will be based on your comments so it's important to have your say."
Revised proposals for reducing England's constituencies from 533 to 501 will be published at the end of the year, or in early next year.
The BCE must report to Parliament with its final recommendation in September next year as the Government hopes to have the changes in place for the scheduled 2020 general election.