The Turnbull government will give itself the power to cancel passports of convicted pedophiles under a deal reached with the Senate crossbencher Derryn Hinch.

The laws, to be introduced to federal parliament, will prohibit child sex offenders from leaving Australia or holding Australian passports if they are on the national child offender register.

The ban will apply for the duration of the offender’s reporting obligations. Once offenders are off the register, they can apply for passports; while the change was approved unanimously in the Coalition party room on Tuesday, The Guardian Australia came to an understanding that concerns were expressed during cabinet debate by the attorney general, George Brandis, about the impact of the change on first-time offenders.

The government is understood to have taken legal advice before cabinet signed off on the final proposal some weeks ago, and Tuesday’s announcement contained some safeguards.

The justice minister, Michael Keenan, declared the passport ban policy a “world-first” which would deny passports to 20,000 people.

Keenan said many people now on the child offender register travelled overseas in breach of a legal requirement to notify authorities when they planned to leave the country.

“We are determined to do what we can to stop Australians from engaging in child sex tourism,” he said on Tuesday. “It’s an absolutely abhorrent crime.”

The foreign minister, Julie Bishop, told reporters 800 registered child sex offenders had travelled overseas in the last 12 months. “About half of those were in breach of an obligation under state or territory law to notify police of their intent to travel.

Bishop said registered offenders with lifetime reporting requirements would be denied passports for life. This ban would impact 3,200 offenders, but she said offenders with time-limited reporting obligations could apply to a state or territory authority if they had a legitimate reason to travel overseas, and that state or territory authority could provide advice to her about whether the travel should proceed.

Last November the government made a commitment to Hinch a longtime anti-pedophile campaigner that it would pursue the policy.