Labor has guaranteed a political fight with the Turnbull government over plans to toughen citizenship laws, with the opposition warning the changes are a “massive overreach” that could create a “permanent underclass” who will never become citizens.

The Labor caucus voted unanimously to oppose the changes in parliament following earlier public criticisms of the proposal from figures within the party’s Left.

It will instead move to refer the legislation to a Senate inquiry.

Labor’s citizenship spokesman Tony Burke launched a savage attack on the changes, rejecting outright the government’s claim that the legislation was linked to national security.

He said the opposition could not support what would be a “fundamental change in our country”.

“It’s not overcooking it to say this is about who we are as a country,” he said.

He confirmed Labor would oppose extending the waiting time for permanent residents to apply for citizenship and the proposed standalone English language test.

“To lift that to university level is a bizarre overreach from this government,” he said.

Setting the test at a level which many Australian-born citizens could not meet was an “act of snobbery on the whole country”, and “guarantees we will have a new permanent underclass” of people who could never gain citizenship.

Asked by The New Daily if Labor could support a less-difficult language test, Mr Burke said the existing citizenship test was sufficient.

He said the government risked having “a group of permanent residents who live here their entire lives and are never invited to pledge allegiance to Australia”.

“[To] never be able to be told by the Australian government, ‘You belong.’ That is a fundamental change in our country and we will not support that change occurring,” he said.

The New Daily previously reported the Human Rights Commission warning that setting the English test at IELTS Level 6 would set a standard beyond the language skills of “many” Australian-born citizens.

Linking the tough new laws to national security, the government wants prospective citizens to wait four years as a permanent resident, rather than 12 months, pass a standalone English test, pledge their allegiance to Australian values and demonstrate they have integrated into society.

Mr Dutton and Prime Minister Malcolm Turnbull immediately condemned Labor for opposing the changes.

“[Labor is] disrespecting Australian citizenship by failing to recognise that integration, citizenship and the harmony and the mutual respect that comes from shared political values that unite us, that requires a respect for citizenship,” Mr Turnbull said. 

Mr Dutton said Labor’s concerns about extending the waiting period and the English test were “red herrings”.

During Question Time, he said while the opposition was divided, the majority of Australians would support the changes.

“This is not some crazy right wing course, it is mainstream thinking,” he said.

“We aren’t going to back down because we have spoken … to the Australian public about their ideas in this space and they fully support the agenda of the government.”

He noted that the extension of the waiting period to four years was comparable with other nations, such as eight years in Germany, and four years in the US.

“Over the course of that four years, people can have the ability to demonstrate that they have integrated into Australian society, they have abided by the laws and the values of this country and they can become Australian citizens.”