The government has been defeated in the House of Lords over changes to the television licence fee rules.
Peers narrowly voted that there should be no move to decriminalise non-payment of the fee before 2017.
Ministers want to keep open the option of making a change when an independent review reports in the summer.
The BBC has said decriminalisation could cost it up to £200m a year, warning channels may have to be closed as a result.
Last year, MPs backed plans to give the government power to decriminalise non-payment of the licence fee, currently £145.50 a year for a colour television.
But in the Lords, a cross-party amendment, preventing any change before the next licence fee settlement begins in April 2017, was approved by 178 to 175.
Conservative peer Lord Grade of Yarmouth, a former chairman of the BBC, said he was "deeply concerned" about the uncertain effect of decriminalisation on the BBC's budget.
He said he would "love" to see the licence fee decriminalised, but added: "There are risks the enemies of the BBC will see it as an opportunity to then move the compulsory element of the licence fee and move the BBC to a subscription model which would completely undermine the whole concept of public service broadcasting."
The vote amends the Deregulation Bill, which will now go back to the House of Commons.