Sir Hugh wants police independence retained
Police chiefs in England and Wales may quit if a Conservative government forced directly elected commissioners on them, Sir Hugh Orde has said.
Sir Hugh, head of the chief constables' association, told the BBC police independence was "absolutely critical".
The Tories want elected officials with powers to hire or fire police chiefs, set budgets and policing priorities.
But Sir Hugh said any idea the police were under "political influence" could undermine democracy.
BBC home affairs correspondent Danny Shaw said the Conservatives had made clear they would not be deflected from their plans, although they are still consulting on the details.
At last year's party conference the Tories outlined some proposals, saying rather than being "directed by and accountable to the home secretary" they wanted chief constables to be accountable to local people.
They outlined plans for police commissioners - civilian workers who would set the police budget, appoint and dismiss chief constables and set local policing priorities in England and Wales.
But Sir Hugh, the former chief constable of Northern Ireland who took over as head of the Association of Chief Police Officers (Acpo) this year, said colleagues would resist being told how to protect the public by locally-elected leaders.
In an interview for BBC Radio 4's Today programme, Sir Hugh said: "Even the perception that the police service of this country
is under any political influence, I think that suggests you cannot argue that you are a proper democratic society. It's as simple and as stark as that.
"Every chief officer fully understands the need to be held accountable. "We must be operationally independent in terms of how we deliver policing. We should not be influenced by anyone who has any potential or suggestion for a political basis."
Sir Hugh suggested the Conservative plans would be a resigning issue.
"I would not be surprised to see chief officers not want to be part of a system where they can be told how to deliver policing," said Sir Hugh.
"There will be no votes in protecting people from terrorism, from organised crime and from serial rapists that cross the country because they won't be local and they won't get you votes."
It follows a row over the resignation of Metropolitan Police head Sir Ian Blair, who blamed Conservative mayor of London Boris Johnson for forcing him out.
Labour had considered introducing directly elected police authorities - which scrutinise forces and set policing priorities - in England and Wales.
But the government dropped the plan last December -then home secretary Jacqui Smith said she feared they would become politicised.
On Friday Home Secretary Alan Johnson called on the Conservatives to withdraw their commitment, saying: "We are faced with the very real prospect of police chief resignations under Conservative plans to politicise the police."
He added: "It must be clear that chief officers, and chief officers alone, are responsible for running their force."
And Lib Dem home affairs spokesman Chris Huhne said: "The last thing British police need is an elected sheriff leading the shootout at the OK Corral.
"Accountability must come from a broad-based police authority elected to represent all strands of the local community."
The Conservatives declined to comment on Sir Hugh's interview.
Sir Hugh said all the political parties were too closely focused on the number of officers on the beat to grasp the need for fundamental reforms to how police are organised.
He said the majority of chief officers wanted to replace the current 44 forces with larger regional ones better placed to tackle major investigations including terrorism, serious organised crime and internet-based fraud.