QANTAS management is warning the airline could ''go under'' if the state-owned Etihad is allowed to buy enough of a share of Virgin Australia to allow it to start undercutting Qantas on its profitable domestic routes.

The chief executive of Qantas, Alan Joyce, and a small delegation has been in Canberra this week lobbying the government and the opposition over Etihad's push into Virgin, warning Qantas could not compete with a state-owned rival backed by a bottomless pit of funds from the airline's owner, the United Arab Emirates.

Threatened ... Alan Joyce has been lobbying the government and the opposition over Etihad's push into Virgin. Credit:Rob Homer

Sources familiar with discussions said Qantas argued that either the Foreign Investment Review Board should limit the scope of Etihad's purchase of Virgin or Qantas should be freed of the constraints of the Qantas Sale Act - which restricts foreign investment and Qantas's business options - to allow it to compete on a level playing field.

Otherwise, the airline warned, ''we could go under''.