Bill Shorten has furiously rejected Scott Morrison's accusation that Labor dragged its feet on national security reforms.
The prime minister on Friday confirmed a Sri Lanka-based Islamist terror group was responsible for bombings in Sri Lanka which killed 253 people at churches and hotels on Eastern Sunday.
Mr Morrison then hit out at the opposition for reluctantly supporting reforms including laws cracking down on foreign fighters, enraging Labor's leader.
"This bloke should be ashamed of himself, playing political games especially in the shadow of the shocking Sri Lankan murders," Mr Shorten told reporters in Melbourne.
"He loves to be on the high ground, this prime minister, but he never fails to reach for the bottom of the barrel when it suits him."
On bipartisan support for reform in the area, Mr Morrison noted Labor reluctantly supported reforms since the coalition government came to power in 2013.
"I can't recall too many occasions when we haven't had to drag the Labor Party with us when it comes to dealing with these issues," the prime minister said.
Laws to block Australian foreign fighters returning home from entering the country for up to two years by a ministerial decision were introduced in February.
Under the legislation, the minister could revoke the exclusion order to allow a person to enter with a return permit, which may include conditions relating to when and how the person enters the country.
"It was our hope to pass that legislation and I was disappointed that Labor once again dragged their feet on that legislation," Mr Morrison said.
Labor's foreign affairs spokeswoman Penny Wong said the opposition had given support to national security legislation over the past five-and-a-half years.
She said the foreign fighters bill had unanimous agreement from parliament's intelligence committee but did not have time to pass during Mr Morrison's "part-time parliament".
Mr Morrison said there were links between the Sri Lankan group and the Daesh network which provided support to the terrorists including targets.
"I can confirm based on the advice that we have received that it was a locally based Islamic terrorist organisation that we believe is responsible for those heinous and cowardly attacks against Christians," he said.
"This is a very important issue and it is one that instinctively the Liberal and National parties respond to and always make the right calls on."
