Alec and Kit are sitting in the hall fighting over a Poundland catalogue.

“Mine!”

‘No, mine!”

“MINE.”

The source of the argument is a picture of a family pack of fun-sized Crunchies. The boys jab at the image of the packet with increasing rage.

“I saw it first!” they shriek in unison, pulling opposite sides of the page.

Here I’m afraid Kofi Annan and I part company. After minimal negotiation the catalogue goes in the bin. The Crunchie dream has died. Having endured years of sanity-eroding bickering my patience over non life-threatening disputes has worn thin.

Seven years ago, as I pushed my adorable first baby around the park (and yes, it was probably sunny), I had no greater concern than which home made meal to defrost for his tea and where to stop for my latte. Motherhood really was a doddle. When I think of it now, the image is actually sepia.

Fortunately I had no idea then that within a few years my main role as a mother would be that of a human shield, a fragile and often ineffective barrier against the verbal and physical grenades my sons like to explode in each other’s faces.

Kit may have lost this particular argument

I rapidly discovered that no possession is too small and no subject too trivial to spark tears, shouting and, usually, a good punch-up. Last week it even extended to unspoken thoughts.

When Kit asked my husband to get his bike out of the shed Harry, seven, exploded with rage.

“He’s copying me!” he shouted. “That’s just what I was going to say.”

The list of flash-points in our house is endless, but includes an epic struggle over who has the orange bowl at breakfast (a rota was instigated), a standoff whereby the twins would only sit in the left hand car seat (their seats were identical) and a nightly row over the angle of the bedroom door (too much light for Kit, too dark for Alec).

As toddlers Alec and Kit, five, fought over who would hold my right hand – both refusing to hold my left which was, of course, free. Whoever failed to get the right hand would then freeze on the spot and refuse to move until said left hand eventually swooped down on them and propelled them unwillingly up the pavement.

On World Book Day Alec and Kit were given the same books by their nursery. When we settled down to read them all hell broke loose. It turns out I was reading Alec’s version of Grumpy Cat so therefore Kit boycotted the reading. In the end Grumpy Cat (with whom I was starting to have quite a lot of sympathy), was read twice – once from each book.

Alec and Kit have developed a bedtime ritual of taking on the persona of a baby animal. Every night it’s a different animal, yet the conversation is pretty much the same.

“I is a baby tiger”, says Kit.

“Awww! I wanted to be a baby tiger!” is the inevitable response from Alec.

Two loud sighs.

“Fine – you be the baby tiger,” says Kit. “I’ll just be a piece of air.” And with that he turns dramatically to face the wall.

“OK then,” says Alec happily.

Constant bickering does funny things to the parental brain. Rather than refusing to be drawn into the boys’ whine-fest, I occasionally find myself capitulating to the most ludicrous demands simply so I don’t have to listen to another second of arguing. At my lowest point I once moved round our dining table at three minute intervals after an interminable row about who was going to sit next to me during the meal.

Harry has developed more subtle guerilla tactics.

When Kit fell off the sofa recently Harry bandaged up his leg and pushed him around on a ride-on school bus which acted as his “wheelchair”. At story time, Harry sat with Kit and “explained” the plot to him.

“Mummy,” he said in a stage whisper. “We’re pretending – even though it’s actually true – that Kit doesn’t know anything.”

As if to prove his point, Kit smiled gratefully.

If there is the sound of a wail from the lounge, I can be fairly sure that by the time I get there Harry will be in another part of the room deeply engrossed in a crack in the wall. Once he tried a different approach. With Alec clutching a red mark on his cheek and Harry culpably near his victim he put his head in front of Alec’s hand and said brightly, “Right, now see if you can hit my head.” Unused to such an invitation, Alec stopped crying immediately and duly whacked Harry. That ploy was not repeated.

The one thing certain to unite the warring factions is an intervention from me. Driven to breaking point recently, I exploded through the lounge door and demanded that a cushion house game which had been dogged by fights, injuries and tears be abandoned once and for all.

“Awww!” Alec said. “We were having so much fun – why did you have to spoil it?”