GPC chair Dr Richard Vautrey said it was 'imperative' that the April 2019 deadline was honoured by the government.
The government has said repeatedly that it remains committed to introducing a state-backed GP indemnity scheme from April 2019 as promised last year by former health secretary Jeremy Hunt.
An update published on Thursday confirms it is working to meet that deadline, but that with just over four months to go, details have yet to be ironed out on a range of key factors.
The update says: 'We are currently aiming for April 2019 for the introduction of the state-backed scheme.
But it adds that negotiations with the GPC are ongoing over precisely how it will be funded - although ministers have also set out their expectation that the scheme will be fully paid for from money already allocated to general practice.
The update reveals that the government is still working to acheive a 'satisfactory agreement on funding' to cover the clinical negligence liabilities of GPs and practice staff, and that 'the final details of the scheme remain subject to ongoing discussions with partners including GP bodies, MDOs and commercial insurers'.
Medical defence organisations have called repeatedly for more information to be made public on how the deal will work.
GPonline reported last week that the MDDUS had warned that with so little information available, GPs should not be forced to switch to the 'untested' state indemnity deal from April.
It called for GPs to have the right to opt out, and for the profession to be allowed to maintain their existing indemnity arrangements if they choose to - without facing a financial penalty compared with other doctors.
GPC chair Dr Richard Vautrey said: 'After the BMA’s successful lobbying, the government committed to introducing a state-backed scheme in April next year and it is imperative that this timescale is honoured.
'The precise details of the deal, including the funding, are subject to negotiations.'