Speaking exclusively to GP newspaper during a 30-minute interview on Thursday, the health minister admitted Labour had put pressure on GPs over the last few years.
But he warned that there would not have been such significant investment in the GP contract under David Cameron's Conservatives.
Mr O'Brien's message to GPs was: ‘In order to justify putting the extra funding into the NHS we have to do more for patients. And you have to do more for patients.'
Read next week's GP dated 15 January for the full interview with Mr O'Brien and look out for more video coverage on Healthcare Republic next week.