The future of Brisbane's Cross River Rail project has become more uncertain after Opposition Leader Tony Abbott's announcement his government would prioritise federal funding for roads ahead of commuter rail projects.

Mr Abbott says roads contribute more to national productivity and that state governments should fund commuter rail projects.

Opposition Leader Tony Abbott says the federal government should fund vital road infrastructure ahead of commuter rail projects. Credit:Angela Wylie

The Labor Party has questioned where that leaves Brisbane's two major public transport rail projects – the Moreton Bay Rail Link and Cross River Rail – if the Coalition wins the federal election.

Federal funding for CRR would ultimately be a decision for the existing infrastructure organisation, Infrastructure Australia, if the Coalition won office.