Stalking law call led by Plaid Cymru MP Elfyn Llwyd
A Plaid Cymru MP is leading calls for a new law making stalking a specific offence in England and Wales to stop harassment resulting in violence.
Elfyn Llwyd led a parliamentary inquiry which says that existing laws do not work because they do not define stalking, unlike new laws in Scotland.
"Thousands of people over the last few years have reported stalking and nothing has happened," he said.
The Home Office says it will "carefully consider" all proposals on stalking.
Mr Llwyd, MP for Dwyfor Meirionnydd, chaired the cross-party Justice Unions Parliamentary Group which found that current provisions under a 1997 Act were ineffective.
The MPs and peers said the law also needed updating to take account of the increasing scope for stalking and harassment using mobile phones and computer technology.
"Fewer than 3% of cases that do come forward end up in any sort of custodial sentence," he told BBC Radio Wales.
"We need a free-standing stalking law but we also need to ensure that when these people are apprehended that there's some form of psychiatric or psychological treatment for them, otherwise we're not dealing with the root cause.
"The problem is we don't have any form of definition of what stalking amounts to - we know the effects of it but we don't have a definition.
"The Scots have succeeded and they have a stand-alone stalking law with definitions.
"Over the last couple of years they have seen 320 or 330 cases referred to the procurator (public prosecutor) as opposed to 70 previously.
"We need to catch up with these things and deal with them adequately."
Mr Llwyd said he was encouraged by Prime Minister David Cameron's previous acknowledgement of a gap in the current law that needed rectifying.
"So far, so good - the prime minister has answered me on the floor of the House (of Commons) saying he believes it's time for change.
"I sincerely hope we will have a strong law put in place."