The GPs claim that NHS Heywood, Middleton and Rochdale discriminated against them on the grounds of race and age.
Their allegations initially went unanswered because the PCT argued they were not employees.
But in a pre-hearing, the PCT accepted it is a qualifying body under the terms of the Race Relations Act. This means an employment tribunal can hear the complaints.
'Anyone under the authority of a qualifying body can take a claim to tribunal for harassment,' said Saimah Malik, director of the charity Protection of Human Rights in Public Law, which represents the GPs.
'The PCT is a qualifying body because it determines who goes onto the performers list and who does not.' PCTs' power to award GP contracts is also relevant, she said.
Middleton GP Dr James Anglin, one of the six doctors pursuing the claim, said: 'Because we are on a performers list, the employment tribunal sees us as having more of an employee status.
'GPs were disenfranchised from employment tribunals and the court system through their supposed independent contractor status. This meant that every PCT could legally not answer for their actions. We are now enfranchised.'
Lesley Mort, executive director of integrated commissioning at NHS Heywood, Middleton and Rochdale, said: 'We are co-operating with legal proceedings relating to this case and will support a fair and transparent hearing.'
A substantial number of respondents to GP's Rate Your PCT survey complained about racial discrimination by their PCT. 'There is a real possibility that the floodgates will be opened,' Ms Malik said.
- Full results and analysis of GP's Rate Your PCT survey healthcarerepublic.com/rateyourpct