In November 2014 Fiona Mactaggart MP added an amendment to the bill concerning prostitution, aimed at criminalising the purchase of sex. In the bill's debate in the House of Commons, John McDonnell MP argued against the amendment. He highlighted the lack of evidence for any correlation between the Swedish sex purchase ban and a reduction in numbers of sex workers or their clients, and cited findings "that not only do such measures not work, they actually cause harm". McDonnell quoted Reverend Andrew Dotchin, a founding member of the Safety First Coalition: "I strongly oppose clauses on prostitution in the Modern Slavery Bill, which would make the purchase of sex illegal. Criminalising clients does not stop prostitution, nor does it stop the criminalisation of women. It drives prostitution further underground, making it more dangerous and stigmatising for women." The amendment was subsequently dropped. In March 2015 an amendment was brought forward in the House of Lords concerning migrant workers who are brought to the UK by their employer using "tied visas". These workers are typically foreign domestic workers and they are not allowed to legally leave their job and find employment elsewhere. The system of tied visas, introduced in 2012, has been compared to the Kafala system of employer-sponsored workers used in some Middle East countries. The amendment would have given workers in the UK using tied visas the right to change employer, but it was rejected by the House of Commons. Experts in the issue were skeptical of the bill, believing that it had many shortcomings. Parosha Chandran, a human rights barrister and United Nations expert on trafficking, claimed that "the bill is very poor on victim protection". Anthony Steen, who advised on the legislation and chairs the Human Trafficking Foundation, claimed that the bill failed to focus on the needs of victims of trafficking in the UK. "The bill is wholly and exclusively about law enforcement – but it shouldn’t be enforcement-based, it should be victim-based", he said. Human rights group Liberty argued that the bill should have:   On 26 June 2017, Lord McColl introduced a private member's bill in the House of Lords to "make provision about identifying and supporting victims of modern slavery". The Modern Slavery (Victim Support) Bill completed its House of Lords stages on 10 May 2018 and was presented to the House of Commons on 18 May 2018. The Bill amends the period of assistance and support offered to victims with a conclusive grounds status to 12 months after the period of reflection and recovery ends. One of the aims of the Home Affairs Select Committee's inquiry into prostitution legislation, which began in January 2016, was to examine the impact that the act had had on trafficking for the purposes of prostitution and whether further measures were needed to help those involved in prostitution to leave it.