Fewer than one in five people think the new police and crime commissioners (PCCs) will make a positive difference to the support victims receive, a survey has shown.
The controversial commissioners, who will be elected on November 15 to replace existing police authorities in 41 areas outside London, will be put in charge of ensuring that provision for victims meets local needs and is value for money.
Actress and knife crime campaigner Brooke Kinsella, whose brother Ben was killed in a knife attack in June 2008, urged people to elect PCCs who "who will put the needs of victims and witnesses first".
But a survey of almost 2,500 adults in England and Wales for Victim Support found only 18% think they will make a positive difference.
Ms Kinsella said: "My family and I know how important it is to get emotional and practical support after a crime. I don't think anyone traumatised by crime should be left to fend for themselves."
Fewer than a quarter of those polled online thought victims would be a priority for PCCs, who will have the power to set force budgets.
It also found that fewer than one in two people (46%) knew about the elections and almost nine out of 10 did not know what PCCs will do - more than half (55%) did not know very much and almost a third (30%) said they did not know anything.
Victim Support urged potential PCCs to sign up to five promises to victims. The pledges include to be "open and accountable to victims and witnesses", to ensure that they get the high quality help and support they need, when they need it, and to make the police more victim-focused.
It also calls for them to help victims and witnesses to have a louder voice in the wider criminal justice system and to improve the experience of victims.
Javed Khan, the charity's chief executive, said: "The future of support for victims is in the hands of PCCs. But our survey shows that most people don't know about PCCs, what they'll do or have little faith that they'll prioritise victims' needs. It's now time for PCC candidates to stand up and prove to the public that they are committed to victims."