Chopstix at the Designer Outlet is giving away free spring rolls to anyone named Greg, Gregg, Gregory or a close variation, as part of a nationwide campaign called Punch Up Your Lunch. The offer runs from 30 October to 23 November and requires customers to register on the chain's website before claiming their voucher in store.

The promotion follows research commissioned by Chopstix suggesting more than half of Britons have avoided bringing certain lunches into the office to avoid offending colleagues, and over a third have changed seats or left a room because of someone else's meal. Chopstix says the campaign is designed to encourage more adventurous desk lunches generally, and Greggs specifically.

Staff at the Designer Outlet branch are understood to be preparing for a modest but determined influx of men holding out bank cards, library cards and, in at least one case, a laminated darts trophy, as proof of a name that is not technically on any official document.

Gary Tench, Area Manager at Tench Paper Solutions in Westlea, said he had looked into it and while his name is Gary, he did once sign a leaving card 'Gregg from Accounts' as a joke that nobody laughed at, and felt this gave him a moral claim to a spring roll. He added that he intended to raise the issue with the branch manager in the spirit of what he called 'reasonable ambiguity'.

Brenda Pask, 72, of Old Town, who has lived there since before it was old, said she had never needed to prove her own name to anyone in her life, least of all to get a spring roll, and that in her day you simply told the butcher who you were and he believed you. She said she wasn't one to gossip, but the Gregg two doors down had already been down there twice and was now telling people his middle name was also Gregg.

Chopstix has not said what happens to a Craig who turns up hopeful, nor to anyone called Gregory who feels the shortened form is doing all the work. The spring roll, meanwhile, remains entirely indifferent to who is eating it.