It was once assumed that a knife and fork always went together - but research out today suggests the cutlery double act is being split up.
Sales figures released by a major department store showed forks were outselling matching knives by almost two to one.
And etiquette authority Debrett's said the research pointed to a wider relaxation in dining habits, with less formal meals and more fast food snacks.
"In years gone by, our parents and grandparents sat down and had formal meals together," said etiquette expert Jo Bryant, of Debrett's.
"But that doesn't happen so much these days and people don't learn table manners from an early age like they used to."
The figures released, by Debenhams, showed sales of large, main-meal forks were almost double those of matching knives at its 155 stores nationwide.
In London, customers bought almost three forks to every knife, although in other areas, including Birmingham, Belfast and Doncaster, sales were more even, Debenhams said.
Ms Bryant said: "We've certainly found that table manners are more relaxed and the declining use of the knife is part of that.
"We do eat more fast food, more rice and pasta dishes, where knives are not needed but people are often trying to use their fork as a knife when they shouldn't. That's when table manners decline.
"It's definitely something people should remember."
Debenhams said it had launched a "Civilised Dining Campaign" to promote dining table manners.
"Using both a knife and a fork to eat has held this country in good stead for centuries - it's one of the mainstays of being British," said Debenhams spokesman Ed Watson.
"It's all about maintaining standards, so we want to act now before the single fork habit becomes ingrained in the next generation."
A Debenhams spokesman said the exact sales figure for knives and forks would not be released but added it "runs into the thousands".