A target date for the switch to digital radio is 2015
The government could face a public backlash over its plans to switch national radio stations over to digital transmission, peers have warned.
The Communications Committee of the House of Lords says there is "public confusion and industry uncertainty".
It said people were still buying analogue radios which will be out of date in a few years' time.
The government has set a target date of 2015 for national and regional radio stations to switch over from FM and AM.
But the committee has warned there could be a "major public reaction" against the plans unless ministers explain what is happening and address listeners' concerns.
It says between 50 and 100 million analogue radios will become largely redundant after 2015 and around 20 million car radios will need converters.
The committee recommends more advice be given to retailers and consumers, while a "sensible" industry scrappage scheme could benefit manufacturers and retailers of digital radios.
More help needed
The committee also believes the BBC's decision to close two digital-only stations - 6 Music and the Asian Network - sends a negative signal to consumers.
And it calls for a switchover help scheme for the elderly and disadvantaged, similar to the one for television switchover, with more information made available in hard copy, through voluntary organisations.
The committee had strong concerns about car radios, and pointed out that while 20% of all radio listening happened in cars, only 1% of all cars had the capability to receive digital stations.
The Society of Motor Manufacturers and Traders told the committee that incorporating digital radios into new models by 2013 would "be a challenge, but achievable".
But some 20 million older cars would need to be converted to receive digital stations, at the expense of the owners.
The report said: "We recommend that the government, in collaboration with the manufacturers, should provide guidance to the public on in-car digital listening, including advice on conversion kits available and likely to be available within the timeframe of digital switchover."
UTV Media, which runs TalkSport radio and has been opposed to the switching off of analogue, welcomed the Lords committee report, suggesting the case for the switchover has not been made.
Managing director Scott Taunton said: "Before passing the Digital Economy Bill, it is crucial that the government acts to ensure that digital radio switchover will not occur unless it is driven by the listener, and that local commercial radio stations remaining on FM will not be left to wither on the vine."