There we all were. Sitting on the bus. Minding our own business. More or less. As less as you can be in these days of mobile phones. The woman seated directly behind me was sharing her complicated love life with everyone within earshot. A man at the very back was bellowing into his phone, which was to all intents and purposes redundant. Tinny, discordant sounds were leaking very loudly from the earphones of a pie-faced youth at least three rows away. In other words, just a normal, everyday journey on a London bus.

The bus stopped. As they do. And more people got on. Including a yummy mummy, her progeny and her fancy tractor. When my nieces and nephews were babies and toddlers, pushchairs were small, light and could fold up so that they resembled something akin to an extra large, particularly unwieldy umbrella. It wasn’t easy. Trying to fold the chair with one hand with a wriggling, squalling baby clamped under your arm while attempting to disentangle small fingers from the mechanism. Simultaneously clutching a couple of splitting plastic bags and hanging onto the collar of a toddler with a death wish. No it wasn’t easy but that was how it was. Everybody managed.

I’m not suggesting that those folding pushchairs were ideal but we’ve gone far too far the other way. By all means have a sturdier type of chair. But theres no call to take the piss. I mean, really! The modern pushchair seems to be a hybrid of a small car, an off road vehicle and a tractor, judging by the wheels alone. Unnecessarily large, completely antisocial, these engines of Beelzebub have no place on a bus. Literally. There is no room for them. Modern buses allow up to two pushchairs; one of these monstrosities causes enough problems on its own.

They protrude into the aisle, making it impossible to get past unless you are thin and agile, and even then it’s a squeeze. God forbid you should be on crutches, a bit shaky on your pins or somewhat overweight. No chance. The bus is effectively cut in two with people crammed on either side of the obstruction. Bags and clothes get snagged on the handles, shins get scraped and yummy mummy herself adds to the problem as she blocks the passageway, impervious to the glares of the other passengers. No spatial awareness to speak of. But she wouldn’t care anyway.

There’s a whole class of mums these days that believe they have a divine right. I have a friend who calls them ‘Putney mothers’, the sort of mothers with these antisocial pushchairs, who cluster on pavements with their progeny, forcing others to walk in the road. They let their children take up seats on the bus when there are older people standing. Of course they’re not confined to Putney, nor are they all yummy mummys. They come in all shapes and sizes and types. The thing that puzzles me is why they are on the bus at all.

Judging from the size and opulence of the pushchairs, they’re not short of a bob or two. I’m pretty sure they all have cars. So why don’t they drive them? Of course there’s the obvious fact that the engine of Beelzebub may not fit in the boot of an urban hatchback. Making mummy a bit stupid as well as selfish. However, most of them drive enormous cars that wouldn’t be out of place in Texas – all bulging cattle bars and Humvee tyres – so the Xtra-Xtra large pushchairs should be no problem. I’m not saying I want them to drive. I don’t. However, if you are going to use public transport have a thought for others. Don’t try and fit the pushchair equivalent of a tractor on a bus. Since many of these mothers persist in doing so, with the pushchairs getting ever larger and more antisocial, I can only assume it’s an extreme case of showing off. The female equivalent of a small penis.