Treasurer Morrison weighs into Cowan fight

Treasurer Scott Morrison has weighed into the battle for the marginal WA seat of Cowan, attacking Labor candidate Anne Aly over border protection.

Ms Aly last week fended off attacks by Justice Minister Michael Keenan who said the counter-terrorism expert showed poor judgment by helping a controversial self-styled Islamic preacher have his jail sentence reduced.

Mr Morrison increased the pressure on Monday saying no one had been stronger on border security than Cowan Liberal MP Luke Simpkins.

"Luke Simpkins is someone who can both represent the many different communities in his electorate - at the same time you will not find him going weak at the knees on border protection and I cannot say that for his opponent," Mr Morrison told 6PR radio in Perth.

"She's against Labor's own policies.

"Labor just don't have the mettle when it comes to border protection."

Dr Aly says the government supported her deradicalisation work with People Against Violent Extremism and that she has been targeted in a "despicable smear campaign".