Theresa May says she wants to see a bill that will make upskirting a criminal offence pass through Parliament "soon" - after one of her own MPs blocked it.
Sir Christopher Chope has faced criticism from his own party for objecting to the private member's bill.
If passed, someone who takes a photo under a victim's skirt in England and Wales could face two years in prison.
The PM said she was "disappointed" the bill had failed to progress.
The bill was expected to sail through the Commons on Friday, but parliamentary rules mean it only required one MP to shout "object" to block its progress.
Sir Christopher's intervention was met with shouts of "shame" from other MPs.
Ministers have criticised him, with Justice Secretary David Gauke tweeting his disappointment.
But his backbench colleagues have gone further - Tory MP Nick Boles tweeted that Sir Christopher was a politician "whose knuckles dragged along the ground".
And George Freeman, who used to lead Theresa May's policy unit, said the move was "an affront to parliamentary democracy".
Minister for Women Victoria Atkins said the government will allocate time for the bill in Parliament to ensure it does not get pushed down the list of private members' bills.
Sir Christopher has yet to speak out about his intervention, but upskirting victim Gina Martin - who started the campaign for the new law - said he told her he objected "on principle" because it "wasn't debated".
She told the BBC he said he "wasn't really sure" what upskirting was. "I said, 'well, I can help you with that'," Ms Martin added.
Liberal Democrat MP Wera Hobhouse, who brought the private member's bill to Parliament, also criticised the "out-of-touch Tory" for "sabotaging" it.
She has asked for her bill to return to the House on 6 July.
Dawn Butler, Labour's shadow minister for women and equalities, said it was "absolutely disgusting" that the bill had been blocked.
Justice minister Lucy Frazer said the government was "committed to making sure upskirting becomes a criminal offence and have every expectation that this will happen".
So why did Sir Christopher object?
By Mark D'Arcy, BBC parliamentary correspondent
Sir Christopher is a leading member of a group of backbench Conservatives who make a practice of ensuring that what they see as well-meaning but flabby legislation is not lazily plopped on to the statute book by a few MPs on a poorly-attended Friday sitting.
And - after all - this is a bill to create a new criminal offence, for which people can go to jail.
So, however worthy the cause, he insists on proper, extensive scrutiny, and he has spent most Commons Fridays for the last 20 years doing just that.
Ms Martin said she remained "hopeful" and had arranged a meeting to discuss it with Sir Christopher.
She started the campaign to change the law after two men took a picture up her skirt while she was at a concert in London's Hyde Park last July.
Police said they were unable to prosecute as the picture was not graphic enough because she was wearing underwear.
What is the current law?
- There is no law specifically naming and banning upskirting in England and Wales - victims and police are currently only able to pursue offences of outraging public decency or as a crime of voyeurism
- Upskirting has been an offence in Scotland since 2010 when it was listed under the broadened definition of voyeurism
What are the limitations of the current situation in England and Wales?
- Voyeurism only applies to filming actions taking place in private
- Outraging public decency usually requires someone to have witnessed the action but upskirting is often unobserved
- Unlike other sexual offences, people don't have automatic right to anonymity
What does the new law propose?
- As well as carrying a maximum two-year sentence, it would also allow, in the most serious cases, those convicted to be placed on the sex offenders register