Two Labour constituency parties have made a formal complaint about the selection process for two key Scottish seats.
The constituency parties of Rutherglen and Hamilton, Larkhall and Stonehouse have written to Sir Keir Starmer and Scottish Labour leader Anas Sarwar.
They say they have been “inundated” with complaints by local members about a “lack of transparency”.
The Scottish Labour Party said the process was properly administered.
In the letter, seen by the BBC, the Constituency Labour Parties (CLPs) claim that members are concerned about the “integrity” of selections and say they “cannot continue campaigning until this matter is resolved”. They also say there has been a “lack of involvement of local members.
The letter says the CLPs are “fighting every day” to give communities choice.
“They understand the need to select strong candidates to join them in that fight without delay, but for candidates to have any credibility, it is vital that members have full confidence in the selection process used,” it says.
The CLPs are asking for a pause to the current selection and a “full investigation” into the process so far.
The Scottish Labour party runs its own selection process for candidates. Seats are “twinned” to ensure gender balance.
A Scottish Labour spokesperson said: “Selection processes for Labour Party parliamentary candidates are properly administered in full accordance with procedures set by the Scottish Executive Committee.
“Scottish Labour is pleased to have a number of fantastic candidates on the shortlist who will be champions for Rutherglen and Hamilton West.”
A by-election could be called in the seat of Rutherglen and Hamilton West, as the incumbent MP Margaret Ferrier faces a 30-day ban from the House of Commons for breaching Covid rules.
Ferrier spoke in Parliament in September 2020 while awaiting the results of a Covid test.
She then took the train home to Glasgow after being told she had tested positive.
She lost the SNP whip and has since pleaded guilty to breaching Covid rules. She was sentenced to carry out 270 hours of community service.
The charge stated that she had failed to self-isolate and had “exposed people to risk of infection, illness and death”.
She is appealing the recommendation from the Commons’ Standards Committee.