MPs fiddled their expenses as a “displacement activity” because Parliament had become irrelevant and ineffective, Commons Speaker John Bercow has said.
Mr Bercow suggested the 2009 scandal was as much a symptom of decades of decline as "malice or corruption" as he urged action to ensure Westminster kept up with the modern world in a speech to the Hansard Society.
He said after becoming Speaker in June 2009 he feared for the future of parliament, describing it as a "virtual corpse".
"The blunt truth is that the expenses debacle was a particularly embarrassing layer of icing on an especially unappetising cake," he said.
"The reality in 2009 is that the House of Commons as a meaningful political institution, an effective legislature, had been in decline for some decades and was close to reaching the point where it had become, to distort [19th century journalist] Walter Bagehot slightly, a dignified part of our constitution without much actual dignity.
"The House appeared to be little more than a cross between a rubber stamp and a talking shop which had taken to collective activity such as the imaginative interpretation of what might be a legitimate expense claim as much as an odd form of displacement activity as out of any shared sense of malice or corruption."
But an influx of new MPs in 2010, the novelty of coalition, and procedural changes such as forcing ministers to answer more urgent questions had sparked a revival.
"Far from being in the final twitches of our mortal life, the virtual corpse has staged an unexpected recovery," he said.
"It turns out that in the spirit of Dr Who, the parliament elected in 2010 has not been about death but about regeneration."
He used the speech to announce the creation of “a Speaker's Commission on Digital Democracy”.