Election debate a 'bore': Greens

The federal election debate was a "bore" that failed to spell out major differences between the two major parties, Greens leader Christine Milne says.

Senator Milne says Prime Minister Kevin Rudd and Opposition Leader Tony Abbott displayed their harsh treatment of asylum seekers and both failed to commit to substantially raise emission reduction targets.

"Last night's television debate was really a bore and a draw between the red and blue ties," she told reporters in Melbourne on Monday.

"The people of Australia really were the losers.

"Major differences of policy were not on show and that's why it needed the Greens there."

Mr Rudd pledged to bring in a marriage equality bill within 100 days if elected, but Senator Milne said that both Labor and Liberal blocked the Greens' bill for marriage equality before the election was called.

"What he should do is declare that Labor has a policy position to end discrimination, that's where the Greens are coming from."

Senator Milne said both Mr Rudd and Mr Abbott showed their cruelty on the asylum seeker issue by focusing on border security, rather than a humanitarian crisis.

There was also no discussion about reducing the gap between rich and poor, and while both leaders spoke about education, neither acknowledged they backed cuts to universities, she said.

Senator Milne said neither party pledged to substantially increase emission reduction targets and Mr Abbott was focused on "last-century" polluting infrastructure which propped up coal-fired power.

She said that if Mr Rudd wanted to protect the Great Barrier Reef in future, as he claimed, he had to explain why he was ducking the question of expanding north Queensland's Abbot Point coal terminal.

"We are not going to be able to save the Great Barrier Reef from bleaching and acidification and being smashed by more extreme weather events until we significantly reduce our emissions," she said.