The firms have been in talks since April (The Lawyer, 24 April) and according to Michael Ball, head of Weightmans' employment practice, a decision on the merger will be reached in the next week.
But a source close to Weightmans says: "My guess is that it will not happen."
Commenting on whether the talks are positive, Hill Dickinson managing partner David Wareing says: "It depends on what you mean by it going well. We have been taking it very steady."
Wareing also disputes that a decision will be made within the week, saying that it is an "ongoing matter".
But a source says that both firms have been quibbling over terms of partnership, specifically regarding the status that some partners will enter the merged firm with.
The revelations coincide with Weightmans' senior partner stepping down just three months into his second two-year term of office.
Mike Edge is returning to fee-earning and deputy senior partner Ian Evans will step into the role until an election in September, when the newly created role of managing partner will be voted on. The role is being introduced as part of a wide-ranging restructure of Weightmans.
Under the restructure, the firm's current policy group, which takes responsibility for management issues, will be replaced by a strategy board, and the firm will take on a finance partner for the first time.
The managing partner will also appoint new heads of each of the departments (or "business centres", as they will be known).