Media playback is unsupported on your device Media caption Lord Morrow rejected criticism of his bill, saying it would be law by the middle of 2015

The Northern Ireland Assembly has voted by 81 to 10 in favour of making it a crime to pay for sex.

MLAs spent several hours on Monday debating the measures, which formed part of a private member's bill on human trafficking and exploitation.

Clause six of the bill makes it illegal for someone to obtain sexual services in exchange for payment.

Northern Ireland is the first part of the UK to vote in favour of the measure.

There is still some way to go before the bill becomes law, but the prospect of a ban on paying for sex in Northern Ireland has taken a significant step forward.

Supporters said the clause in Lord Morrow's private member's bill tackled a main driver for human trafficking.

Opponents included Justice Minister David Ford who claimed it would be difficult to enforce.

Significant step

The Democratic Unionist Party (DUP) said it would accept some Sinn Féin amendments, a rare example of agreement between the parties.

Sinn Féin had reserved judgment, but Caitriona Ruane finally signalled the party was prepared to support the move

Finance Minister Simon Hamilton of the DUP also proposed an amendment that would make it an offence for anyone to force someone else into marriage.

The amendment was drawn up by Mr Hamilton, whose department has responsibility for registering births, marriages and deaths.

The amendment reflects the introduction of a similar offence in England, Wales and Scotland earlier this year.

Image caption Sex worker Laura Lee said Northern Ireland would regret the move

There were more than 60 amendments to the Human Trafficking Bill.

Outside the assembly on Monday, a group of sex workers wearing face masks made their opposition clear.

'Laughing stock'

Sex worker Laura Lee said Northern Ireland would regret the move.

"I think it will be absolutely disgraceful and I think that we'll be able to show it as the failed model for what it is and we'll be the laughing stock of Europe," she said.

A trafficking victim, known only as Anna, watched the debate and rejected the argument that a ban would push sex workers further underground.

Image caption Trafficking victim Anna told the BBC's Mark Devenport that she rejected the argument that a ban would push sex workers further underground

"The people who are saying that these laws, if they are put in place, would force it underground, I would say they are just trying to create panic when there is not any reason to panic because this is already underground," she said.

"The only thing which would go underground would be the sex industry which would have to lose major income."

The debate lasted until late on Monday night.

Earlier, Mr Ford said he supported the spirit of the bill, but believed that a clause that proposed prosecuting those caught paying for sex made it impractical.

Research published last week suggested that about 17,500 men pay for sex each year in Northern Ireland.

The study by Queen's University, Belfast, was commissioned by the Department of Justice in response to Lord Morrow's proposed bill.

Meanwhile, another poll has indicated that almost 80% of people in Northern Ireland support the criminalisation of paying for sex.

The Ipsos Mori survey found support for the Human Trafficking Bill was strongest among people aged between 16 to 34.