Delivering his first budget reply speech, Opposition Leader Angus Taylor promised to index tax rates in line with inflation, claiming the move will deliver workers an extra $1000 a year, four years into the policy.
Under his plan, the bottom two tax brackets - covering people earning between $18,201 and $135,000 - would be indexed from 2028/29.
The top two tax brackets would also be indexed from the 2031/32 financial year.
Cabinet minister Mark Butler said Mr Taylor was "huffing and puffing on the dog whistle" he borrowed from Pauline Hanson's increasingly popular party.
"There were a long list of vague, hollow promises," he told ABC RN on Friday.
"These things might be good ideas, but until you actually tell these million people how you're going to pay for a tax plan like that, they're not worthy of much serious attention."
The opposition leader also promised to strip welfare payments from permanent residents, including access to JobSeeker and the National Disability Insurance Scheme, claiming the move would save billions of dollars.
The reforms would be grandfathered, Mr Taylor said after his speech, so current permanent residents wouldn't be left worse-off.
"We're not taking anything away from anyone," he told ABC TV.
Mr Butler said temporary visa holders have never had access to the NDIS, and the people who would be affected under the proposal include permanent residents.
"What Angus Taylor has now said is ... you are not going to get the support of a government scheme to which you have contributed through your taxes and I think that's an extraordinary change," he said.
Under a broader crackdown on migration, Australia's intake of foreigners would be tied to the number of homes built every year.
"This much I promise: the coalition will deliver one of the biggest cuts to immigration in Australian history," Mr Taylor said, without providing detailed figures for his migration targets.
MP Barnaby Joyce, who defected to One Nation in December, said Mr Taylor was effectively reading off his new party's script and said he'd never seen the coalition pushed further to the right on immigration.
"I think the Australian people ... feel uncomfortable about where (migration's) off to, and they're demanding of governments of all ilks to give them a sense of security," Mr Joyce told the ABC.
Migrant advocates responded angrily to the opposition leader's speech, accusing him of attempting to "chase votes with fear and division".
"Taylor's comments tonight are inflammatory and desperate," Asylum Seeker Resource Centre deputy chief executive Jana Favero said in a statement.
