The federal Liberals are getting started on repealing some of the previous government's sweeping — and controversial — changes to how people get or lose Canadian citizenship.

Immigration Minister John McCallum has introduced a new bill that, if passed, would remove terrorism or other crimes against the national interest as grounds for revoking citizenship from dual nationals.

The legislation would also restore citizenship to anyone who has been affected by those provisions; officials said Thursday there is one person to whom that would apply, but did not identify the individual.

"Canadian citizens are equal under the law," McCallum said in a statement. "Whether they were born in Canada or were naturalized in Canada or hold dual citizenship."

The bill also shortens the length of time someone must be physically present in Canada before qualifying for citizenship, and allows time already spent as permanent residents to count towards the residency requirement.

The Conservatives had also expanded who needs to pass language and knowledge tests before qualifying for citizenship; the Liberals are returning to the previous age requirement of 18 to 54.

But the bill also makes some new changes, including adding those serving conditional sentences as people barred from seeking citizenship.

None of the changes would take affect until the bill becomes law and coming-into-force provisions are established.

When the Conservatives introduced the new law in 2014, it led to accusations that they were creating two classes of citizens, but they argued the move was in keeping with laws in other countries.

Citizenship can still be removed from those who've obtained it via fraudulent means or misrepresentation.

In an email to The Canadian Press ahead of the announcement, former Conservative immigration minister Chris Alexander said the changes his government made were in keeping with Canadian values.

"Terrorism, espionage and treason are serious crimes, representing gross acts of disloyalty. They are far more serious violations than covering up minor crimes from one's past — a common form of misrepresentation," he said.

The Conservative bill was attacked as setting a dangerous precedent and even challenged, unsuccessfully, as unconstitutional.

When the bill was rolled out, there was particular concern in ethnic communities that, over time, the criteria to revoke citizenship would expand to include convictions for lesser crimes.

The current law also has a provision that requires people to declare they intend to continue residing in Canada if granted citizenship. That raised concerns among some new Canadians that they could lose their citizenship if they moved outside of Canada. The new law would repeal this provision.

Attacking the bill was a key element of the Liberal election strategy in heavily diverse ridings, and they promised to overhaul the law during the campaign.

In 2014, the latest year for which full figures were available, 262,600 people were granted Canadian citizenship.

Proposed changes

Here's a snapshot of the current law and the proposed changes.

Grounds for revocation

Current law: Those convicted of crimes against the national interest such as terrorism, treason or spying and who have dual citizenship could have their citizenship revoked if they are dual nationals.

Proposed change: repeals those provisions and restores citizenship of anyone who has been affected.

Residency

Current law: requires people to have been physically present in Canada for four out of six years before qualifying.

Proposed change: people will have to be physically present for three out of five years before qualifying.

Language and knowledge requirements

Current law: Everyone between the ages of 14 to 64 must pass language and knowledge tests.

Proposed change: Applicants between the ages of 18 to 54 must pass language and knowledge tests.

Stephanie Levitz, The Canadian Press