With gasoline prices topping $4 per gallon and Americans' concern about climate change increasing, energy issues are at the forefront of the US presidential campaign. Here is where Republican John McCain and Democrat Barack Obama stand on major questions of energy policy.

Energy security
Both candidates acknowledge the need for the US to lessen its dependence on foreign oil. McCain last week proposed allowing oil companies to drill in US coastal waters. Obama opposes lifting the more than two-decade old ban.

Ethanol
Obama supports subsidies for corn-based ethanol, and would mandate that all new vehicles be able to run on ethanol blends.
McCain favours eliminating the subsidies.

Nuclear energy
McCain last week called for the construction of 45 new nuclear power plants by 2030.
Obama is open to expanded nuclear energy, but said producers must address concerns over transparency, security of nuclear fuel and waste, and waste storage.

Electric and hybrid vehicles
McCain today called for big federal government tax incentives and a research prize to encourage development of "zero-emissions" automobiles.
Obama also proposes federal aid, including consumer tax incentives to encourage development and proliferation of low-emissions autos.