The Rejoin EU Party said Labour’s decision to deny permission to Greater Manchester mayor Andy Burnham to stand in the by-election “appears to have thrown the contest wide open”.
Labour earlier announced Angeliki Stogia, who is currently a Manchester councillor, had been selected as their candidate for the poll.
Rejoin EU said the party wanted to “offer voters a clear pro-EU alternative to the cautious, ineffective or, in some cases, downright hostile policies on Europe held by other major parties”.