Healthcare professionals met to discuss the response to the pandemic at an RCGP pandemic summit in London last week.
Merseyside GP Dr Simon Abrams, medical director at Urgent Health UK, said that although he now feels the service coped, at the time he felt it was 'sitting on the brink'.
Dr Abrams estimated Liverpool's primary care services would have had to deal with 7,000-14,000 patient contacts per week if pre-pandemic predictions had come true.
'As a reality check, in the surge in July (2009) we dealt with less than 1,000 cases a week,'
he said, and even then it was 'incredibly busy'.
He also said areas that failed to set up dedicated swine flu centres had struggled.
An RCGP report, At The Front Line Of Swine Flu, points to problems in the containment phase when GPs needed protective gear and swabs for home visits.
Dr Maureen Baker, RCGP pandemic flu lead, said: 'There was a lot of difficulty getting hold of supplies. There was also a difficulty about who was going to pay for it.'
East London GP Dr Kate Adams, who works for the Tower Hamlets out-of-hours service, criticised the Health Protection Agency. She said it needed 'a reality check' over expectations of GPs to report swine flu cases and collect samples.
Dr Abrams concluded: 'If out-of-hours and in-hours services are going to deal with the predicted highs of a flu pandemic, you can see there's an awful lot of work to be done.'