Police will deliver personal warnings to known domestic abusers as part of a pioneering strategy responding to dramatic spikes in such violence around Celtic and Rangers games, as Glasgow braces itself for the first meeting of the notorious rivals for nearly three years at Hampden Park on Sunday.

“It’s been a very effective strategy,” says former DCS John Carnochan, co-founder of Strathclyde’s groundbreaking violence reduction unit. “It’s saying to the abuser: we know what happened last time, we’re watching you, don’t do it again. But it’s also saying to the wife: we remember, and we’re here.”

Although women’s groups make it clear that football is not a cause of, nor an excuse for, domestic abuse, the evidence of the link between intimate violence and match days is overwhelming, in particular when Rangers and Celtic are involved, even relating to the day of the week when games are played.

In 2011, Strathclyde police found that on Old Firm days domestic abuse incidents increased by up to 138.8% on Saturdays, followed by an increase of up to 96.6% on Sundays, and an increase of up to 56.8% on weekdays. Further analysis by the Scottish government reported incidents of domestic abuse increased by a third on weekends when Old Firm fixtures were held.

“It’s definitely going to be a hard weekend,” says Mary (not her real name), who has been living in a women’s refuge with her two children for a year after fleeing over a decade of abuse from her partner. “I’m really nervous about Sunday, and I certainly won’t take my children into town.”

Mary is a Rangers fan; her husband supports Celtic. “He’d go out to watch the football and I’d go round to my sister’s, just thinking ‘What mood will he be in when he gets home?’. I’d like Rangers to win but to keep the peace I’d want Celtic to win.

“After the match, I’d be trying to turn the television off in case the highlights came on and made him angry. The kids were too scared to talk about it. But then, he didn’t need an excuse. I’ve been so used to sitting with my stomach in knots from 2pm on a Saturday. It’s only recently that I’ve started to relax on Saturday afternoons.”

Mhari McGowan, head of service at Assist, which works with Police Scotland to support victims of domestic abuse, has witnessed first-hand the strategy of visiting known abusers with a history of violence around the time of Old Firm games. “Victims feed back to us that they appreciate that someone is looking out for them and has their eye on them.”

While McGowan has no plans to put on extra staff over the weekend, she expects the service to be busier on Monday: “Our antennae are definitely up. I did breathe a sigh of relief when Rangers came out of the top league. But perpetrators are not daft: they may change their behaviour if they know they’re being watched at specific times.”

The key message of Strathclyde’s violence reduction unit was prevention, which Stephen House, now chief constable of the unified Police Scotland, applied with laser precision to domestic abuse when he set up the domestic abuse task force in 2010. “No other police constable has made such a difference,” says McGowan. An elite unit of investigators, it was the first team of its kind in the UK to tackle domestic abuse in the same way that detectives would a murder.

“You can say it’s just picking on Rangers and Celtic fans,” says John Carnochan, “but there are 50,000 men there [at Hampden] and the odds are that a lot of them will be abusers. It’s putting domestic abuse on the front page, or the back page, and starting the discussion that this is not acceptable any more”. Carnochan is writing for Saturday’s Daily Record calling for both Rangers and Celtic football clubs to publicly condemn domestic violence.

“There are huge issues around masculinity in the west of Scotland,” he adds. “Men aren’t sure what their role is in life. What is it to be a man when you don’t build ships or make steel? Women have coped much better in terms of the gender shift.” Carnochan points out that more than a third of cases of domestic abuse are witnessed by children. “If you don’t fix domestic violence then you can’t fix violence. Behind closed doors is where it’s reinforced.”

Pamela McElhinney of Glasgow East Women’s Aid has observed first-hand the escalation of domestic abuse incidents leading up to and shortly after Old Firm fixtures. “The chaos these games create means that it doesn’t matter if the perpetrator’s team won or lost. Women told us that even when their partner’s team won, it often made no difference.”

But McElhinney is clear that the responsibility for abuse lies with the abuser. “The combination of alcohol, possibly drugs, and conflict with others at the game and after it in pubs is a contributory factor. But alcohol, drugs, or football matches do not cause abuse. What they do is make an already abusive individual even more abusive.”