Plans to change the law to make it illegal to pay for sex have attracted criticism from a number of groups.
Commons leader Harriet Harman said ministers were to look at how Sweden brought in such a law.
The English Collective of Prostitutes said legal brothels would be preferable and the Liberal Democrats said a ban could put women in more danger.
Buying or selling sex is legal but many prostitution-related activities, such as soliciting and pimping, are not.
The government is carrying out a wholesale review of the laws around prostitution, with the aim of reducing demand and increasing the safety of sex workers.
Home Secretary Jacqui Smith said there would be a "mini review" looking at lessons from Sweden, after Home Office minister Vernon Coaker's fact finding trip there in the new year.
UK PROSTITUTION LAWS
Prostitution is not illegal
Brothel-keeping is a criminal offence
Kerb-crawling and soliciting are also illegal
The Sexual Offences Act 2003 introduced penalties against those who sexually exploit children
Trafficking adults or children for the purposes of committing sexual offences was also outlawed
Meanwhile, Ms Harman said the planned move would counter international human trafficking which sees girls bought and sold by criminals in the UK.
The government has toughened its stance on prostitution in recent years, after initially considering "tolerance zones".
Plans to permit small brothels, with two prostitutes and a maid, to operate legally also appear to have been shelved.
But plans to make selling sex illegal have attracted criticism from a number of groups.
The English Collective of Prostitutes attacked Ms Harman's support for the Swedish system and urged her to look at New Zealand's system of legalising brothels instead.
Spokeswoman Cari Mitchell said the Swedish system of criminalising men who buy sex had forced prostitution further underground and "made women more vulnerable to violence".
Similarly, Sarah Walker, also from the group, said the deaths of five prostitutes killed in Ipswich last December was largely due to young women being forced underground.
She called for the government to concentrate on factors such as poverty, homelessness and debt which she said pushed many to prostitution.
A man is due to stand trial next year in connection with the Ipswich killings.
Liberal Democrat spokesman David Howarth said a ban was not the answer, arguing that it could put women in more danger.
He said: "Evidence from Sweden in making prostitution illegal has shown that it doesn't help in reducing human trafficking. It, in fact, increases violence against women and makes the practice of prostitution far more risky for all involved.
"Outlawing prostitution completely will mean that men will be far less likely to come forward to help with prosecutions for fear of criminalisation themselves."
Alan Gordon, vice chairman of the Police Federation, also spoke out against further criminalisation.
"A move towards legalising state-run facilities would certainly be something which could be examined, as they could possibly eradicate underground prostitution and therefore have a knock-on effect on human trafficking," he said.
Regarding the plans put forward by Ms Harman, a Home Office spokesman said it was "too early to say" whether any changes to the law would apply across the UK or just in England and Wales.
The Sexual Offences Act 2003 made it illegal to buy sex from anyone aged under 18 and introduced tough penalties for trafficking adults and children for the purposes of sexual exploitation.
It is not illegal for an individual aged over 18 to work as a prostitute in off-street premises but where there is more than one prostitute, the owner of the premises can be prosecuted for keeping a brothel.
Many of the activities associated with street prostitution, such as soliciting and kerb-crawling, are also illegal and it is against the law to advertise sexual services on cards in telephone boxes.
The current laws are largely aimed at reducing nuisance for local neighbourhoods, a Home Office spokesman said.
But Harriet Harman, who is also deputy Labour leader and equality secretary, says more needs to be done to tackle demand and protect women.
She told BBC Radio 4's Today programme: "Just because something has always gone on, doesn't mean you just wring your hands and say, 'Oh well there's nothing we can do about it'.
"We do need to have a debate and unless you tackle the demand side of human trafficking which is fuelling this trade, we will not be able to protect women from it."