Opposition Leader Bill Shorten says it took some time for the full magnitude of Operation Fortitude to sink in before he realised it was a bad "quasi police state" look for Melbourne.

Mr Shorten was initially not too critical of the Border Force operation, saying Labor stood for law and order, but after it was abandoned, he strongly denounced it.

Speaking with reporters on the sidelines of the West Australian Labor conference on Saturday, he described it as "one of the most catastrophically silly ideas I've seen this government do".

"To be honest, I couldn't believe what I was hearing," Mr Shorten said.

"I'm sure, by the way, that regardless of one's politics, when you first heard about this, you would have gone 'what?'

"As more facts came to light yesterday, I don't think there's a single Victorian and indeed a single Australian whose jaw just didn't hit the ground.

"Truly, how dumb is this government some days?

"I fly out of Melbourne early yesterday morning and Mr Abbott goes and wrecks confidence in my home town as soon as I leave the state."

Mr Shorten said the government needed to take responsibility for the "quasi police state" plan, rather than blaming whoever wrote the news release.

"You cannot find a coalition minister, Mr Dutton or Mr Abbott, to explain what's gone on.

"Here's my prediction: they're going to throw another poor old uniformed person under the bus, so to speak, to take the rap."