A bill that would pay for modernizing the state's transportation system is back before the Legislature.

The House on Wednesday is expected to debate an amendment that Gov. Deval Patrick insists is needed before he can sign the bill. The amendment would raise the gasoline tax if tolls on the western portion of the Massachusetts Turnpike are removed in 2017.

House Speaker Robert DeLeo opposes the amendment. Without it, Patrick has promised to veto the bill, saying the state must replace the transportation revenue that would be lost if the tolls come down.

Lawmakers could also take up Patrick's veto from the state budget of $177 million in local aid to cities and towns. The governor blamed the veto on the uncertainty over the transportation bill, which contains new taxes needed to balance the budget.

[Associated Press]