Conservative MPs have developed a habit of not doing what they are told - and they have found it to be quite addictive.
David Cameron has to deal with backbenchers who are more rebellious than any of any party since 1945, figures published on Tuesday revealed.
Kettering MP Philip Hollobone, who has rebelled a massive 129 times against the government, tops the list of 148 Conservatives who have voted against the prime minister's wishes since 2010.
The extent to which Conservative MPs do not fear the party whip was set out in a report by Nottingham University's Philip Cowley and Mark Stuart.
Speaking at the launch of the report in central London on Tuesday amid backbench turmoil over Europe, Cowley observed that on the EU, Conservative rebels would always "keep coming back for more".
"Europe is a particularly toxic issue," Cowley explained. "It's like a bad curry, it keeps repeating on you quite noxiously."
Much of the rebel tendency on the Tory benches is put down to the unusual situation of coalition government - with Conservative MPs frequently being asked to vote for legislation that was not in their manifesto including House of Lords reform.
Downing Street also finds it harder to convince MPs to vote the way the prime minister wants on the basis that they owe him for winning the general election - because he did not.
Worryingly for Cameron, the MPs first elected in 2010 are among the most stubbon. New MPs can usually be expected to tow the party line, or be pushed into it by party Whips. However since the election a whopping 85% of the 2010 intake have rebelled against the government - making up 90 of the 148 rebel gang.
And it is not just the prime minister who has trouble keeping his MPs in line. Aside from those who have served in government in some capacity, there is now not a single Lib Dem MP who has not rebelled against the government.
The most rebellious Lib Dems so far are Andrew George and Mike Hancock, who have both defied the government a total of 44 times. And previously loyal Sarah Teather has rebelled ten times since losing her job as an education minister in September 2012.
The findings come as several Tories insisted they would press ahead with plans to vote against the government's Queen's Speech over the issue of Europe.
On Tuesday David Cameron had hoped to quell or split the rebellion by offering a last minute draft Bill on the EU referendum. However John Baron, the ringleader of the Tories who plan the almost unprecedented vote on an amendment against their own government's legislative programme, said the prime minister's offer was "second-best".
So far 78 MPs have signed the rebel amendment, including 67 Tories, six members of the Democratic Unionist Party and five from Labour, including former ministers Frank Field and Kate Hoey.