Andrew Martin: Pyjamas are a man's way of wearing pink

"Style is revealed in little things," writes Bernhard Roetzel in his excellent Gentleman: A Timeless Guide to Fashion, "like how you dress when there is nobody to see you." Speaking as a professional author – that is, a man who spends more time than most in a state of undress – I read those words with a considerable feeling of guilt. My attire for most of the morning consists of loose pyjamas and even looser dressing gown, a look that is, I believe, known in police circles as "indecent exposure".

I therefore sympathised with the managers of a Dublin welfare office, who have announced that the wearing of pyjamas on the premises by claimants is not acceptable. A Tesco in Cardiff and a school in Belfast have also banned pyjamas. Well, I say pyjamas, but I suspect that most of the transgressors were dressed in what is called "loungewear", examples of which dominated the shop window of my local Gap at Christmas. The thing about loungewear is that it brings you up to a presentable standard sartorially as long as no one else is around, but unfortunately the wearer is fatally tempted to venture outside and on to public streets in it. Why? Because loungewear looks like ordinary wear from a distance, and there is usually no fly hole on the men's trousers, so there's no danger of being arrested for a public order offence.

The loungewear habit might claim the growing number of househusbands (it was announced this week that 62,000 men were classified as looking after the family or home last year, compared with 21,000 in 1996), and the possibly overlapping numbers of the simply unemployed. In fact, loungewear might be described as the quintessential garb of our recessionary times. It is associated with the social trend called "cocooning" – that is, not going out in case something bad happens, and I do have some sympathy with this.

When you think about it, it is a lot of hassle to go outside. At least, it is if you do it in the traditional way, with your shoes on, hair brushed etc. I am reminded of a celebrated 18th-century suicide note: "All this buttoning and unbuttoning."

There is a (fairly) honourable tradition of wearing clothes suitable for indoors only, and shops in that most dandified of London streets, Jermyn Street, always have pyjamas in the windows. "As far as a gentleman is concerned," somebody who seemed to think he was one of the breed explained to me, "the purpose of pyjamas is to let him wear colours he wouldn't be allowed to wear on the streets." Hence, the lurid pinks and yellows, violent clashes and strobing stripes seen by the wife; but of course she doesn't really count.

No?l Coward looked good in a dressing gown, as did Sid James in Bless This House (67th in the 2004 poll of Britain's Best Sitcom), whose plotlines always involved him being harassed and disturbed while in bed. And those who sneer at men like me who work at home should remember that Winston Churchill won the Second World War while "working from home", either in bed with a cigar, or holding court in the No 10 bunker wearing a special one-piece romper suit he'd created.

But loungewear must ultimately be condemned. It is associated with an attempt to avoid the strife of the wider world, but it only promotes more of the same. As we sit on our sofas in our comfy clothes, rising only to take delivery of Amazon packages (it being just about acceptable to take delivery of parcels in loungewear), our health lapses, our motivation decreases and our high streets crumble. I foresee a time when expensive public information campaigns will be mounted, urging us, not to eat five a day or take up cycling, but simply to open the door and step outside, once in a while.