Long-term bonds may fund infrastructure

The federal budget could include the introduction of 30-year bonds to help fund the government's $50 billion national infrastructure plan.

Treasurer Scott Morrison has not ruled out the introduction of 30-year bonds to fund major projects.

It is understood Treasury is examining the bonds, which are used in the United States and Britain to finance infrastructure.

"When you're looking at funding infrastructure into the future you want as many options as you can available to you, particularly when you're in a very constrained fiscal environment," Mr Morrison told reporters in Canberra on Friday.