Financial support for the A350 would take the form of a repayable launch investment, whereby the Government would recoup the money and gain royalties.
The company is keen to emphasise that the plane's wings, to be manufactured in the UK, will be safe, light and fuel-efficient. The wings use a composite material with a high level of carbon.
Good Relations will also stress that thousands of jobs within Airbus and supplier companies depend on the A350's production. The 200 to 300-seater plane is likely to compete with US rival Boeing's 7E7, which is also under development.
The agency will in particular aim to build goodwill among the Department for Trade and Industry, the Treasury and environment ministers, as well as backbench MPs.
Airbus UK head of government affairs Katherine Bennett said: 'We need to ensure Airbus's profile remains high in political circles as a UK success story.'
Good Relations has been taken on for a three-month initial contract. The account will be led by senior consultant Estelle McCartney, with managing director James O'Keefe providing strategic counsel.
Bennett said she might put PA out to tender thereafter. She joined last July from Vauxhall Motors, where she was head of government relations.
Airbus is owned by European Aeronautic Defence and Space Company and BAE Systems.
Its A380 double-decker 'superjumbo' starts commercial flights in 2006.