Peers defeated the government by backing a crackdown on sex-for-hire predators.
The House of Lords backed by 206 votes to 176, with a majority of 30, the creation of a new offence, amid fears that the existing law would fail vulnerable victims of such exploitation.
The upper house also backed without a vote a move to target those facilitating adverts for the illegal practice with the threat of a £50,000 fine.
Although confirmed as a sex offense in 2017, the upper chamber heard only one person had been charged in a sex-for-hire case and just last year.
Introducing the amendment to the Policing, Crime, Punishment and Courts Bill, Labor MP Lord Ponsonby of Shulbrede said: ‘The law itself has been made extremely difficult for victims of sex for hire for get justice.
“According to the law, victims must be legally defined as prostitutes, which is a huge obstacle to their access to justice.
“Another reason this scandal continues virtually unchecked is that landlords can very easily advertise sex for rent in their properties.”
Online predators attempt to coerce men and women into exchanging sex for accommodation by exploiting their financial vulnerabilities
He was backed by Labor Baroness Kennedy de Cradley, director of campaign group Generation Rent, who said: ‘Online predators try to coerce men and women into trading sex for a home by exploiting their financial vulnerabilities .
“They used the economic effects of the pandemic as a marketing technique.”
Although only one charge was made, she pointed to research which indicated the practice was widespread with one poll estimating that a quarter of a million women had been asked for sexual favors in exchange for free rent or reduced.
Lady Kennedy said: ‘This is a crime that takes place overtly and explicitly through advertisements on online platforms.
“Yet, although the advertisements are clear in their intent, they are not controlled.
“They are placed without consequence.
“They are largely ignored by law enforcement and online platform providers.”
She added: “No one should ever be compelled by coercion or circumstance to trade sex for their home.
“There is a housing emergency in this country, it continues to reach new lows, so low that sexual predators can deliberately take advantage of people’s desperation to find housing.”
His Liberal Democrat counterpart, Lord Marks of Henley-on-Thames, acknowledged there was “a serious need for criminal legislation to end what is a particularly nasty form of predatory behaviour”.
In response, Home Secretary Baroness Williams of Trafford said: ‘It is a heinous phenomenon, which takes advantage of very vulnerable people, and it has no place in our society.’
Stressing that sex for hire cases could be prosecuted under existing law, she said: “Action will be taken against landlords who exploit vulnerable people.
“This behavior is simply not tolerated.”
In a subsequent government defeat, peers backed a decision to allow the immediate introduction of exclusion zones around schools and vaccination centers to prevent harassment by anti-vaxxers.
The Lords voted 157 to 145, majority 12, for a Labor measure allowing the acceleration of public space protection orders, which can be used to disperse people from a designated area.