Britain won plaudits for its landmark Modern Slavery Act but charities said on Thursday that traffickers have nothing to fear from politicians' pre-election promises on the slave trade.
"Despite the passing of the Modern Slavery Act, we still fail the majority of the victims of modern slavery in Britain today, while traffickers go unpunished," said Aidan McQuade, director of Anti-Slavery International.
"The next government needs to go much further and focus on supporting victims," he told the Thomson Reuters Foundation.
The last of the big political parties released its manifesto on Thursday ahead of a June 8 election that the ruling Conservatives are widely expected to win.
But with the focus on immigration and on Britain's exit from the European Union, charities said there was little in the way of new policies or money to combat the global trade in people.
Nearly 46 million people are enslaved globally, according to the 2016 Global Slavery Index.
In Britain, there are an estimated 13,000 victims of forced labor, sexual exploitation and domestic servitude, most of them from Albania and Vietnam.
"All these manifestos don't describe any practical measures to provide the protection and support that victims need to recover and rebuild their lives," said Kate Roberts, head of office at the Human Trafficking Foundation.
"We would like to see people at risk from trafficking or exploited able to go forward to the authorities without fearing themselves being criminalized," she told the Thomson Reuters Foundation.
It is a big change from two years ago when Prime Minister Theresa May, then working as home secretary, pioneered the Modern Slavery Act, which stood at the vanguard of global efforts to tackle the trade in people.
In Thursday's manifesto launch, May pledged only to review the legislation and to push international bodies to step up the fight- a long way from her previous rallying cry against "the great human rights issue of our time".
The Modern Slavery Act requires businesses to disclose what action they have taken to ensure their supply chains are free of slave labor. It also introduced tougher criminal sanctions for perpetrators and more victim protection.
The opposition Labour party pledged to ensure the act was implemented and to "restore the rights of migrant domestic workers," according to their manifesto launch on Tuesday.
The Liberal Democrats, a smaller opposition party, promised to train police and prosecutors in identifying and supporting victims and to decriminalize sex work to focus police efforts on helping those trafficking into the sex industry.