Prime Minister Kevin Rudd has accused Opposition Leader Tony Abbott of another "appalling error" of foreign policy judgment over his latest comments about the Syrian crisis.

Mr Abbott on Monday described the conflict as a civil war between "two pretty much equally unsavoury sides".

He added that the Syrian opposition included "quite a number of elements that are highly influenced by al-Qaeda".

The prime minister described Mr Abbott's comments as "stunning".

He reminded the opposition leader that 80 countries, including Australia and the United States, recognised the main opposition umbrella group, the Syrian National Coalition.

"If Mr Abbott is the prime minister on Sunday ... is he going to send a direction to our ambassador in New York to de-recognise the Syrian National Coalition?" Mr Rudd told ABC radio on Tuesday.

"This would set off such a reaction in Australian international relations and our standing across the world.

"People wouldn't just scratch their head, they'd walk away in horror at this appalling error of foreign policy judgment."

Mr Rudd earlier seized on Mr Abbott's description of the Syrian conflict as a war between "baddies versus baddies".