Party activists in Edinburgh Southern contacted SNP HQ after relationships with the candidate for the seat, Catriona MacDonald, broke down in March – around six weeks before polling day.
Edinburgh Southern was a key target for the SNP and was viewed as winnable ahead of the election with Scottish Labour incumbent Daniel Johnson protecting a majority of 1,123 votes, making it the fifth most marginal seat in the country.
However, on polling day Scottish Labour saw a swing of 3 per cent in their favour, with Mr Johnson returned with a majority of more than 4,000 following a record 71 per cent turnout in the constituency.
It is understood the constituency association was forced to hold an emergency meeting on Sunday, March 21, due to concerns around how the campaign was being fought.
Following the emergency meeting, SNP HQ were contacted by the constituency association in a bid to revive the campaign’s hopes.
However, it is understood there was no help provided despite the request.
One local SNP source said the campaign was “blighted by an inexperienced candidate”, adding Ms MacDonald’s approach had left activists “alienated rather than mobilised”.
The source said: "Edinburgh Southern is a tricky seat for us, with a respected Labour incumbent. But, with the right campaign, it is absolutely a winnable seat.
"Unfortunately this campaign was blighted by an inexperienced candidate who was neither inclusive of nor communicative with activists and constituency party organisations.
"From the off, the vast majority of volunteers were alienated rather than mobilised, and the party’s positive message did not reach voters. Losing the seat became inevitable very early on."
Alongside similar failures to overturn narrow majorities in Eastwood, Dumbarton and Aberdeenshire West, the failure to win Edinburgh Southern saw the SNP miss out on an overall majority.
The seat was last held by the SNP in 2011 by Jim Eadie, a candidate for the Alba party in the 2021 election.
Another local source said: "Being chosen by the membership to represent them at an election is a tremendous honour.
"To turn on the very activists who nominated you, and blame the volunteers for problems of your own making, is unforgivable.
"[There are] lessons to be learned for future campaigns where hopefully we can unite around a truly grassroots candidate."
A third local source told The Scotsman: “Catriona and her campaign team appeared to view the constituency association as somewhat of a nuisance, and communication was almost non-existent."
Ms MacDonald also ran for the Edinburgh South constituency in the 2019 general election, losing by more than 11,000 votes to Labour MP Ian Murray – a narrower margin than in 2017 when Mr Eadie lost by more than 15,500 votes.
Responding an SNP spokesperson said: "Despite the SNP vote being at a record high in Edinburgh Southern – and with our vote share up 4.4 per cent too – unionist tactical voting with Labour relying on Tory votes prevented another SNP gain this time round."
Ms MacDonald was contacted for comment.