With five weeks to go until the UK goes to the polls, the college manifesto - dubbed #BackGP - warns that a no-deal Brexit will be 'hugely damaging' to patient care.
Leaving the EU without a deal threatens to undermine the NHS workforce, as well as supplies of medicines and medical devices, the college warns.
More than 100 medicines prescribed in primary care are already out of stock in the UK, and the government has barred the export of more than 20 medicines to try to stave off further shortages.
The college warns that with general practice already facing a 'severe shortage of GPs', the situation could deteriorate further if mutual recognition of professional medical qualifications with other European nations ends as the UK leaves the EU.
RCGP chair Professor Helen Stokes-Lampard said the profession faced 'unprecedented' pressures - and warned that 'any political party that ignores general practice does so at the peril of our patients and the NHS'.
General practice currently delivers more than 300m appointments a year in return for less than 10% of the NHS budget, the RCGP manifesto warns, calling for the share of overall funding for frontline GPs to rise to 11%.
The college also calls on the government to deliver an extra 5,000 GPs - a promise health and social care secretary Matt Hancock committed to last year, although he dropped the 2020/21 deadline for the increase set by his predecessor Jeremy Hunt.
The manifesto calls for 'upgraded and purpose-built GP premises, including high-speed broadband for every GP surgery in the UK', repeats a call earlier this year by college chair Professor Helen Stokes-Lampard for '5,000 more GP training places per year in England' and calls for more support for GP teams.
Professor Stokes Lampard said: 'Our patients and the public love our NHS, and for 300m patients a year - and rising - general practice is the frontline of the NHS.
'The main political parties have already made the NHS a key focus of their campaigns, but the last thing we want to see are vote-winning gimmicks. it is vital that their commitments are realistic and that they support our family doctor service.
'The pressures on general practice are unprecedented. Our patients’ needs are becoming more complex and the traditional 10-minute consultation is no longer fit for purpose.
'We need more time with our patients but we are already going above and beyond to try and keep pace with demand, often to the detriment of our own health and wellbeing. We simply don’t have enough GPs and practice staff to cope and patients are having to wait longer and longer for an appointment.
'The next government – whatever its political allegiance – must give GPs and our teams the support we need to do our jobs properly so that we can continue to provide safe and high quality care to our patients, well into the future.'