The UK's former anti-slavery commissioner has described the government's failure to appoint her replacement as "deeply regrettable".

Dame Sara Thornton held the role for a period of three years, ending in April last year and it has been vacant ever since.

The Modern Slavery Act 2015 ushered in the role of a commissioner to give independent advice on modern slavery issues.

Dame Sara believes inaction may be linked to a "conflict of interest" in the Home Office, which wants to row back modern slavery laws.

Asked about the fact her previous role still lies vacant after a year, Dame Sara said: “I don’t know. I think it’s deeply regrettable. Whether it’s deliberate or whether it’s just poor administration and poor bureaucracy, I don’t know.

"But, given the level of public discourse about modern slavery, given that we had the Illegal Migration Bill and also lots of issues about implementation of the Nationality and Borders Act, it seems to me that this is a key appointment and Parliament surely should be informed by the expert views of an independent slavery commissioner.”

“I do think potentially the Home Office has a conflict of interest. I also think that a three-year appointment for this sort of role is not long enough – it needs to be five or seven years so that a commissioner can act without fear or favour.”

Baroness Butler-Sloss, a former senior judge and independent cross bench peer, also expressed dismay that the government has not appointed a successor:

“It’s inconceivable that if this had been a totally objective approach to who should be appointed, that she wasn’t reappointed, and it seems to me that lies exactly in the fact that the Home Office has control.”

Dame Sara also criticised “really concerning” rhetoric around immigration, saying it “undermines the Modern Slavery Act, and it has a hugely chill effect on victims and survivors”. She added that an “overlap between small boats and modern slavery has been greatly exaggerated”.

CARE worked closely with Dame Sara Thornton's department during the passage of modern slavery legislation in Northern Ireland and described her role as key. A spokeswoman said:

"The of anti-slavery commissioner is hugely important as it provides a voice for victims and impartial scrutiny of government activities. Dame Sara was a gifted and passionate advocate for the vulnerable during her tenure.

"Given the hostile, mistrustful atmosphere we are seeing towards modern slavery victims at the moment, appointing her successor is vital. We urge ministers to act."