Regions such as the south west of England could be disadvantaged by changes to the way the government funds road and rail projects, says the Transport Select Committee.
In a report, the committee said a new system from 2015 would encourage private-sector funding.
That could disadvantage regions with less private sector money, said the report.
The South West receives the lowest spend on transport in the country.
Devon County Council leader, John Hart, said he recognised the imbalance.
"That's why we've been lobbying the government," he said.
"We lobbied hard on Dawlish [railway line]. We've been arguing for quite a while now on the need for money to be spent on improving the A303.