The move comes as the Health Protection Agency (HPA) confirms that the death toll from the virus has risen to 29 in the UK. The number of cases of swine flu currently stands at 55,000, although the RCGP estimates around 37,000 cases.
Hospitalisations for swine flu have also doubled in the last week, with the rate highest for children under five.
The government also warned that deaths from swine flu this winter could be between 19,000 and 65,000.
Speaking at a briefing in central London on Thursday, Sir Liam said that the flu line would help to reduce pressure on practices.
Staff at call centres will be provided with a clinical algorithm, developed by clinicians and the BMA, to help identify which patients could benefit from antivirals.