Stalking is to be made a specific criminal offence, David Cameron announced today, as he promised new protection for the victims of this "abhorrent" crime.
The prime minister, who will meet stalking victims at No 10 reception to mark International Women's Day, said the government was determined to ensure "justice is done".
"Stalking is an abhorrent crime. It makes life a living hell for the victims - breaking up relationships, forcing the victims to move house, making them feel they are being watched 24 hours of the day," he said.
"That is why we are explicitly criminalising stalking, to make sure that justice is done, protect the victims and show beyond doubt that stalking is a crime."
Clifford Mills was found guilty of murdering Lorna Smith (pictured)
The move comes after a parliamentary inquiry called for a new offence in England and Wales to be brought in immediately to stop harassment and intimidation turning to murder.
But MPs and peers from all parties warned that a new law alone would not be enough to protect victims and that "fundamental reform" of the system was needed.
Shadow home secretary Yvette Cooper urged the Government to support a Labour amendment to the Protection of Freedoms Bill - which would create a new offence based on the law in Scotland - in the House of Lords on Monday.
"We need rapid progress and we need a new law which is strong enough; half-hearted measures won't be enough," she said.
Clifford Mills was found guilty of murdering Lorna Smith (pictured)
"Victims have already waited too long, and the Prime Minister should support our tough and clear new offence."
Laura Richards, a psychologist who was an adviser to the parliamentary inquiry, welcomed the Government move saying victims were being repeatedly let down by criminal justice agencies in a "scandal that cannot continue".
It follows a year-long campaign by the charity Protection Against Stalking and the probation union Napo.
Harry Fletcher, Napo's assistant general secretary, said: "It is essential that any new legislation ensures that victims are properly protected and perpetrators receive adequate sentences and attend programmes that combat their obsessive behaviour."
Mr Fletcher, also an adviser to the inquiry, said the Government's proposals would be examined in detail to ensure they will effectively deal with the problems of the current system.
Changing the laws on harassment to create an offence of putting someone in fear of violence would always be hard to prove in court, leading to stalkers being convicted of lesser offences and being back on the streets quicker, they warned.
Some 120,000 victims, mostly women, are stalked each year but just 53,000 are recorded as crimes by police and only one in 50 of these lead to an offender being jailed, the inquiry heard.
Just 20 stalkers a year are jailed for longer than 12 months for putting a victim in fear of violence, while some were behind bars for just days and others were sentenced to community orders and "inappropriate" domestic violence courses, campaigners said.
The calls for reform came as a man who stalked his ex-girlfriend on Facebook before stabbing her to death was jailed for life with a minimum term of 21 years after being found guilty of murder.
Clifford Mills, 49, attacked Lorna Smith after inviting her to his flat in Brixton, south London in February last year. He denied murder, claiming he was suffering mental abnormality at the time, but an Old Bailey jury took just 90 minutes to find him guilty last month.
Another stalking victim, Claire Waxman, 35, was awarded £3,500 damages after the High Court ruled the state failed to protect her when charges against her stalker were dropped.
Ms Waxman, who runs a business in Willesden Green, north-west London, complained of "serious and persistent" harassment over eight years by freelance television producer Elliot Fogel, 36.
Lord Justice Moore-Bick said Ms Waxman was entitled to damages in respect of the "alarm and distress caused by the failure of the CPS to pursue the prosecution".
He said: "The state owed her a duty to take proper measures to protect her and was in breach of its duty in failing to pursue the prosecution."
Ms Waxman is expected at today's reception along with Tricia Bernal whose daughter Clare was shot and killed by her obsessive ex-boyfriend in Harvey Nichols in Knightsbridge, London in 2005.
Michael Pech, 30, was awaiting sentencing after admitting harassing Ms Bernal, 22, when he killed her. He then turned the gun on himself.
Home Secretary Theresa May said: "Stalking is an issue which affects many lives, often in devastating ways.
"That is why we are taking it seriously and introducing these new offences. Offenders need to know that they will be brought to justice for making others' lives a misery.
"We will do all we can to protect victims of stalking more effectively and to end this appalling crime."
Under the moves, the Government will bring in two new offences - stalking, and stalking where there is a fear of violence.
Police will also be given new powers of entry to investigate stalking offences, the Home Office said.
At the moment, officers only have a right of entry in respect of conduct that puts people in fear of violence.
Assistant Chief Constable Garry Shewan, the lead on stalking for the Association of Chief Police Officers (Acpo), said the legislation was a "positive step".
"There is no doubt that victims of stalking and everyone campaigning to protect victims from further harms posed by stalking will welcome today's announcement," he said.
"Proposed new powers of entry to investigate stalking offences were specifically requested by police, and improved training and guidance for both police and prosecutors will play a key part to improving our response to stalking victims.
"The key to protecting victims and alleviating the fear and harm is through everyone taking the issue seriously, through extensive awareness-raising and through improved and effective response to stalking by police officers, the Crown Prosecution Service, the courts and the health service."
Click to read David Cameron's blog How We're Tackling Violence Against Women: An Iceberg Under the Surface of Society.