Victims' families are to launch a High Court judicial review of the alleged "deliberate" failure of the authorities in Northern Ireland to properly resource an inquest into their sectarian murders.
Senior coroner John Leckey is retiring later this year and no replacement has been appointed, he told a preliminary hearing of the inquest in Belfast. Once he leaves there could be only one coroner in the country.
Kingsmill is among dozens of inquests dating from the early days of the conflict which face delay because not enough money is available to investigate or there is nobody to oversee fresh hearings.
Mr Leckey said: "I feel for the bereaved families, not exclusively Kingsmill but for other inquests I am involved in. It is a disappointment that is widespread."
Human rights lawyer Kevin Winters, who represents some of the Kingsmill victims, said: "It is farcical to suggest that one coroner can deal with so many legacy cases, it is nonsense."
The Stormont House political agreement signed before Christmas between the five political parties envisaged a system for dealing with legacy inquests but it has been threatened by Sinn Fein's refusal to implement welfare cuts.
Outside the court, Karen Armstrong, a sister of one of the Kingsmill dead, said: "It is a political difficulty, it is a political problem.
"We are not going to lie down and accept it, we will fight until we get another date and they have to make sure there are enough coroners in Northern Ireland to deal with our and many other cases."
A listing to hold the inquest in June was abandoned because legal matters will take longer than anticipated to complete.
Mr Leckey's retirement is imminent. He said: "At the minute there are two coroners.
"I am almost at the exit, leaving one in post, and it is a matter for the Department of Justice (DoJ) to resolve.
"I am not in a position to hold the Kingsmill inquest. There is no coroner able to take up these inquests."
The judicial review will be taken against the DoJ and Office of the First Minister and Deputy First Minister collectively.
Mr Winters said: "It is a disgrace the way the families have been treated, with what many of them believe is the deliberate under-resourcing of the coroner's office."
Ten textile workers were gunned down after an IRA gang stopped their minibus close to the Co Armagh village of Kingmill as they were travelling home from work. They were forced to line up alongside the van and ordered to divulge their religion. The only Catholic worker was told to flee the scene while the 11 remaining were shot. Just one man, Alan Black, survived, despite being hit 18 times. No one has ever been convicted of the murders.