Allowing TV cameras into court could deter victims and witnesses from coming forward to report crimes, a parliamentary committee has warned.
Measures in the Crime and Courts Bill, currently going through the House of Lords, would allow limited access for cameras to some court proceedings in England and Wales.
The legislation will only permit the broadcast of judgments and sentencing decisions in the Court of Appeal, and it will not allow victims or witnesses to be filmed.
But the Parliamentary Joint Human Rights Committee warned that once the cameras were allowed into courts, there could be a "slippery slope" towards greater and greater freedom to film - with damaging consequences for justice.
Committee chair Hywel Francis said: "We are especially concerned about the power in the Bill to lift the current restrictions on filming and broadcasting of court proceedings.
"We agree that justice must be transparent and publicly accessible. But the power in the Bill is too broad.
"The Government's current intention is to limit filming to the appellate courts, with the possible addition of sentencing remarks in the Crown Court in due course.
"However, as currently drafted, it could too easily be extended to include filming of witnesses, parties, crime victims, jurors and defendants - a very different proposition, which could have the unintended consequence of deterring victims and witnesses, and possibly even undermining the fairness of trials.
"It's potentially a slippery slope. We would urge the Government to move more thoughtfully with wider public consultation and a more detailed impact assessment."