Tessa Jowell once described it as “rather cumbersome and inexplicit”.
Ed Miliband struggled to explain it to John Humphrys on the Today programme in November 2010.
"This is about people who are working hard, who are working in an economy - and I take some responsible for our government for this - who are working long hours - we have the longest hours in Western Europe, that has huge implications for our economy and for our society and perhaps we'll come onto that. And they feel squeezed," Miliband tried to explain.
"I've no idea what you mean by the squeezed middle," said Humphrys.
"I define them as people around the average income - both below and above the average income - not people on six-figure salaries," replied Miliband.
But a year on, the phrase "squeezed middle" has been named Oxford Dictionaries Word Of The Year for 2011 – beating Arab Spring, hacktivism and podcasting.
Oxford University Press spokeswoman Susie Dent said the phrase reflected a “clear prevailing mood”.
"Financial hardship and protest on an almost unprecedented scale have scored our language deeply,” she added.
Labour can take heart from the win – it comes a year after David Cameron’s “big society” won in 2010.