Home Secretary John Reid has insisted violent criminals will not be let off with on-the-spot fines.
John Reid says he is remaining tough over violent crime
A leaked consultation paper suggested extending the system of fixed penalty notices to ease the pressure on courts.
Offences included assault, threatening behaviour, theft up to the value of £100 and assaulting a police officer.
But the Home Office said the idea had not been put to ministers, and that Mr Reid would never allow a reduction in punishments for violent criminals.
A spokesman said: "Ministers have not been consulted about these proposals. Most of the suggestions come from police chiefs.
"The home secretary will never approve any lessening of punishments for violent crime."
The consultation document, which proposed extending fixed penalty notices from next year, included other offences such as possession of cannabis and drunkenness.
Magistrates' Association chairman Cindy Barnett told the Times such proposals would undermine the gravity of serious offences.
She said: "These are crimes that involve victims, and sometimes violence, and some of them are at the top end of what government research has shown the public regard as serious.
"They should not be dealt with by penalty notice. What kind of message does this send out?"
Victims of Crime Trust director Norman Brennan said: "As far as I'm concerned, an instant fine should be given to whoever thought up this crazy idea."
Tony Blair was ridiculed in the papers in 2000 when he suggested that drunken louts should be marched to a cashpoint to pay fines.