The Government has made "a shambles" of its flagship criminal justice plans for elected police and crime commissioners (PCCs), Labour has said.
Shadow home secretary Yvette Cooper accused David Cameron of failing to promote the idea in the run-up to the first elections for the new roles on November 15.
She said: "Loads of people across the country still don't know about the elections, what they're for, so I am really worried about what turnout is going to be as a result of this."
Forty-one PCCs will replace Police Authorities, with the power to set budgets and policing priorities and hire and fire chief constables, in the biggest shake-up of policing for 50 years. Supporters say they will boost accountability across forces in England and Wales, but critics believe they could politicise policing.
The Prime Minister admitted in the Commons last week that it would be "a challenge" to encourage electors to cast votes, amid claims turnout could dip below 20% – sparking fears for PCCs' democratic mandate. Labour opposed the scheme but is fielding candidates, the highest-profile being former Deputy Prime Minister Lord Prescott in Humberside.
Ms Cooper criticised the poll's timing, claiming bad weather would deter voters.
"We are doing our best to make it work, but the Government needs to be doing much more," she said. "They have made a shambles of this, for something that was supposed to be their flagship policy."