An extensive plan to save Australia's Great Barrier Reef has been announced by Prime Minister John Howard's main rival in the forthcoming elections.
The reef is made up of many colonies of corals
The move by Labor leader Kevin Rudd has brought environmental issues to the centre of the campaign stage.
Mr Howard has been criticised within his own party for his lack of action on the environment and climate change.
His refusal to sign the Kyoto Protocol is believed to be one factor in his increasing unpopularity among voters.
Mr Rudd has accused the Howard government of failing to act on climate change, a view shared by many voters.
He announced the A$200m (£90m, US$185.5m) plan while on a glass-bottomed boat tour of the reef in Queensland in the north-east of the country.
The Great Barrier Reef, Australia's leading tourist destination, is being damaged by water pollution and rising sea temperatures, which are killing off the millions of coral that make up its 2300km (1429 mile) length.
Mr Howard believes the Kyoto Protocol is flawed
"The Great Barrier Reef is Australia's greatest natural asset," Mr Rudd said.
"We have a responsibility to the next generation of Australians to do whatever we can to properly preserve it."
As well as being one of the natural wonders of the world, the reef attracts a million visitors a year.
Mr Rudd said the bulk of the fund, A$146m (£65.4m), will go towards a water quality grants scheme to encourage landowners to adapt more environmentally-friendly agricultural practices.
The BBC's correspondent in Sydney, Nick Bryant, said the prime minister's perceived lack of action on environmental issues, in particular his refusal to sign the Kyoto Protocol on climate change, is seen as a big vote loser.
Mr Howard has insisted that the protocol is flawed because India and China are not involved and that the economic needs of the country must be considered.
However, it has recently emerged that Environment Minister Malcolm Turnbull tried to persuade him to reverse his policy on climate change on the eve of campaigning.
Mr Howard is said to have rejected the idea for fear of appearing panicky and unprincipled.
The Australian tourist industry is hugely reliant on the reef
Our correspondent says this has reinforced the widely held view that Mr Howard is stuck in the past whereas Mr Rudd has a vision for the future.
Opinion polls suggest that Mr Rudd has a clear lead over Mr Howard in the build-up to the election, due to take place on 24 November.