The Liberal Party has posted an ad on social media linking the arrival of asylum seekers to street crime in western Sydney.

The banner was posted on the Liberal Party of Australia's Facebook page yesterday and was 'liked' by more than 680 people.

"Under Labor, crime is out of control in western Sydney," the ad states.

"If Labor can't even control our borders, then how can they control street crime in our suburbs?"

Accompanying the text is an image of a boat at sea and a picture of police crime scene tape.

While some comments on the Facebook page supported the ad, others were critical.

"I'm a Liberal supporter but this advert is awful," one person wrote.

"Putting boat people and crime in the same sentence, another Scott Morrison dog whistle," another wrote.

Others mentioned that crime in Sydney's west was the responsibility of Barry O'Farrell's state Liberal government.

"Crime in western Sydney is under the power of the NSW state Liberal government. Maybe work out how the Australian parliamentary system works then ask us for your votes," one comment read.

The majority of the more than 430 comments were critical of the ad, but others showed support or sought to explain the ad's meaning.

"General crime? Totally a state issue. Gun crime? Feds should shoulder part of the blame, as customs and imports are their responsibility," one man wrote.

"I agree that it (crime) is a state issue - but the states rely very heavily on federal funding," another wrote.

The ABC has contacted the Liberal Party for comment.