The seating sub-committee of the European Union's standardisation committee is threatening to introduce a minimum seat width of 500 millmetres in the interests of customer comfort.
A recent MORI poll of audiences puts poor seating and lack of leg room high among the reasons why more people don't attend the theatre more often.
But the introduction of such a ruling could pose huge problems for theatre managements. Rupert Rhymes, chief executive of the Society of London Theatre pointed out that it would be difficult to make radical changes to the auditoriums of many West End theatres, not just because of the expense but also because so many of them are listed buildings.
But many provincial theatres are already leading the way. The Theatre Royal, Newcastle, can probably boast the widest UK theatre seats at 580mm; the Royal Exchange, Manchester, notches up a respectable 450mm; and the newly refurbished Birmingham Rep has an equally roomy 460mm.
The just reopened Royal Court in Chelsea, anticipating the EU ruling, is sure to find favour in Brussels with its luxurious 520mm seats which have aeroplane-style adjusatble arm rests.
Some luminaries of the theatre world believe offering the punters too much comfort can be counter-productive.
Veteran director Peter Hall is convinced a degree of discomfort encourages the audience to pay attention and give the actors intelligent feedback. Actor Brian Cox recently ran into trouble in New York by complaining that Broadway theatre seats were too comfortable.
Producer Jack Bellamy felt it was tempting providence to make theatres as comfortable as cinemas. 'I love those big armchair seats you get in the smarter London cinemas, but if you put those into a theatre like the Haymarket, half the audience would be asleep by the interval.'