The Australian government has committed to joining the US in its "Son of Star Wars" missile defence program in Washington next month despite strengthening political opposition to the project.
Defence Minister Robert Hill said the signing of a memorandum of understanding (MOU) at the Australia-US ministerial consultations in the US early in July would formalise Australia's long-term commitment to participating in the program.
"We intend to sign the MOU," Hill said in the statement released on Saturday. "This is a long-term commitment to securing our future and strengthening the alliance."
But the controversial move is facing the resistance of combined opposition parties with Labor sceptical of any benefits and the minor Democrats arguing no agreement should be signed ahead of the upcoming election in which the government could lose office.
Hill said the MOU would provide a 25-year framework under which broad areas of cooperation can be agreed, before entering into more specific arrangements once individual projects were agreed to.
The first area of cooperation would involve research, development, testing and evaluation of technologies that could be used in the missile defence program.
A key initial project would be to jointly undertake some exploratory cooperative research and development activities to investigate the potential for Australia's world-leading over-the-horizon radar technology to be used in missile defence.
Other potential areas for participation in the program included greater cooperation in ballistic early missile warning through ship-based and ground-based sensors, Hill said.
Labor foreign affairs spokesman Kevin Rudd said the opposition had profound reservations about the program, fearing it might prompt an arms race by countries such as China and India, and called on the government to produce evidence of its effectiveness.
"We still don't know whether missile defence systems actually work," Rudd told reporters.
"And furthermore if you seek to construct a missile defence system, does that in turn result in nuclear weapons -- countries in our region to increase their arsenal?"
Australian Democrats leader Andrew Bartlett said no agreement should be signed ahead of an election the government says could be any time from August 7 to late November.
"A government that may have only months left shouldn't be signing Australia up to an expensive 25-year agreement on new weapons," he said.
The left-wing Greens slammed the missile program as the next version of former US president Ronald Reagan's failed "Star Wars" missile defence plan of the 1980s.