Prime Minister Tony Abbott has reassured the Australian public that Border Force officials will never stop them randomly in the streets to check their visas.

Mr Abbott said neither he nor his office had prior knowledge of a joint agency operation in Melbourne, which was cancelled by Victoria Police yesterday within hours of being announced after public outcry and protests in the city's CBD.

Key points: No prior knowledge about Operation Fortitude: Abbott

No prior knowledge about Operation Fortitude: Abbott ABF media release "over the top, wrong"

ABF media release "over the top, wrong" Border Force had planned to check visas in Melbourne's CBD

Border Force had planned to check visas in Melbourne's CBD Blame starts at the top, Shorten says

The controversy centred around the suggestion Australian Border Force (ABF) officers would be on the streets to crack down on visa fraud under Operation Fortitude.

The Prime Minister said an ABF media release that stated officers would be "speaking with any individual we cross paths with" was "over the top and wrong".

"I want to make it absolutely crystal clear, as far as this Government is concerned, people will never be stopped in the street randomly and asked for their visa details," Mr Abbott told reporters in Sydney.

"That's the sort of thing that would never, ever happen in this country."

Mr Abbott said today it was to be a "standard law enforcement operation" and anyone suspected of having a visa issue would be referred to ABF officers in "the normal way".

"Nothing untoward happened except for the issue of a poorly worded press release," he said.

When asked if he or his office was aware of the nature of the operation and of ABF's involvement, Mr Abbott repeatedly said "nope".

ABF Commissioner Roman Quaedvlieg confirmed yesterday the initial media statement was "clumsily worded" and approved at "low-level" by the Commander for Victoria and Tasmania Don Smith, who was directly quoted in the statement.

"You need to be aware of the conditions of your visa; if you commit visa fraud you should know it's only a matter of time before you're caught out," Commander Smith said in the statement.

Following public backlash over the crackdown, the ABF issued another statement saying: "To be clear, the ABF does not and will not stop people at random in the streets ... the ABF does not target of the basis of race, religion, or ethnicity."

A scheduled press conference to reveal details of Operation Fortitude had to be cancelled, after demonstrators began assembling outside Melbourne's Flinders Street Station to protest against the operation.

Victoria Police then issued a statement saying the operation had been cancelled.

Opposition says 'blame starts at the top'

Opposition Leader Bill Shorten has accused Mr Abbott of trying to sheet home blame over the debacle to a "mid-level official".

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 2 minutes 22 seconds 2 m 22 s Border farce: How Operation Fortitude unravelled

"The blame starts at the top. Leadership's about taking the bad news as well as the good news," Mr Shorten said.

"Stop blaming the people in uniforms for what goes wrong and start taking some responsibility."

Greens Member for Melbourne Adam Bandt also said the responsibility lies with the Prime Minister.

"Border Force has turned into border farce and it's a bad General that blames their soldiers for mistakes they have made," Mr Bandt said.