Women trying to end relationships are among those at most risk of being the victims of domestic murder, police research suggests.

A study by the Metropolitan Police has identified women who are at the highest risk of being killed by their partners.

Analysis of all domestic murders and assaults in London over the past two years shows that women who try to end relationships are frequent victims.

The findings also show that the violence is often triggered by pregnancy.

The Metropolitan Police say the study will help them to save lives.

Their main findings were:

• the level of violence quickly escalates, with one in three households having a second incident within five weeks of the first

• repeat victims are much more likely to be killed

• women who try to leave an abusive partner are at a higher risk, especially in the first two months after they leave

• stalking or abusive behaviour by men is a strong indication they can show extreme violence

• pregnancy is often a time when abuse begins or intensifies

The study found victims who try and terminate relationships with men are frequent murder victims.

It said: "Notions of 'If I can't have her, then no-one can' are recurring features of such cases."

"Threats which begin with, `If you were to ever leave me...' must be taken seriously.'

The work also found many incidents happen as a result of discussions and issues around child contact or disputes over custody.

Domestic violence in London

90,000 reported incidents a year Accounts for a quarter of murders Nearly one in three cases started during pregnancy One in four incidents in front of children Half the offenders have criminal history Reported incidents up by three times the average on New Year's Day

A Met spokesman said it was hoped the work would allow police to develop risk assessments with victims and help gather evidence.

But the unit's behavioural analyst Laura Richards, who led the work, said: "It is only a guide and does not provide an absolute or relative measure of risk.

"It must be recognised that escalating violence does not solely depend on the number of risk factors appearing.

"It depends on what they are and how they apply in that situation as to whether there is an imminent risk posed to a particular individual."

Last month the Conservative party launched a campaign to highlight the "hidden" problem of domestic violence over Christmas, by distributing 10,000 posters advertising violence helplines.