Prime Minister Tony Abbott in Rockhampton
Prime Minister Tony Abbott in Rockhampton Chris Ison

OPINION: Tony Abbott has destroyed his cred on Defence

TONY Abbott has wasted his only play.

The former Prime Minister may now face scrutiny by the Australian Federal Police after a classified Defence white paper was leaked to the media.

Tony Abbott denies he was the leak that led to excerpts being run in the national media, but the question is still being asked.

In a statement, he wrote

"I don't leak, I don't background against colleagues.

"If I've got something to say, I say it.."

The classified documents landed in the hands of journalist Greg Sheridan -- a long-time friend of Mr Abbott.

It included quotes from Mr Abbott describing his shock and being "flabbergasted" at his party's plans to delay Australia's acquisition of 12 submarines by up to 10 years.

Mr Abbott will be asked about the leaks by journalists at press conferences to come.

That question will be asked quietly by his colleagues and loudly be his enemies.

The Prime Minister and the AFP are now asking the same thing.

Whether or not he was the one who handed over the document, however, is just one part of the problem.

By speaking about it, he showed his cards.

Mr Abbott's key strength is on national security. Even as Prime Minister he did not mince his words, even if he was criticised for what he served up.

Think his vow to shirtfront Russian President Vladimir Putin.

But a former Australian Prime Minister giving a spray about classified Defence documents?

That is not the behaviour of someone who takes security seriously. He has the clout to make his views crystal clear to those in power without having it splashed in the media.

This was a PM whose government ran Operation Sovereign Borders so strictly that almost any query about the operation was dismissed because it would not discuss "on-water matters".

Now he is publicly weighing in on classified documents? 

Whoever leaked the documents wanted to show Prime Minister Turnbull as being weak on national security.

But a blow that could have done really damage to the PM has now been minimised thanks to Mr Abbott's outburst.

And if the time ever comes when Mr Abbott attempts a Lazarus-like return to the top job, colleagues will think back to this moment when he thought it wise to vent his spleen on unlawfully-released documents.

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