It is back, and this time it might bite the Tories even harder than usual: Europe, the issue that has threatened to tear apart the Conservative Party for decades.
Prime Minister David Cameron faces an embarrassing Commons defeat later today when MPs debate the EU budget.
A rebellion is brewing on the Tory backbenches because eurosceptics want the budget cut, while the PM plans to go no further than to demand a real-terms freeze, an inflation-only rise of a little over 2% a year.
The budget will cover the period 2014 - 2020.
Some in Brussels are calling for a budget increase of nearly 7% - at a time when the EU is demanding draconian austerity measures from Greece and other countries worst hit by the eurozone crisis.
This has been like a red rag to a bull to the Tory right, who are organising a Commons ambush.
Tory MPs Mark Pritchard and Mark Reckless will need 40 others to rebel with them to bring about a Government defeat now that Labour has said it will vote against the Government.
Past performance suggests they will fall short, but they could come close with MPs like Bill Cash and John Redwood garnering support for their cause and urging Mr Cameron not to "cave in" to pressure from Europe.
One eurosceptic Tory MP is even using the argument that a Commons rebellion will strengthen Mr Cameron's hand when he goes into the budget negotiations in Brussels next month.
The Prime Minister is beset on all sides - not only the right of his own party but also from Ukip which is attracting disillusioned Tory eurosceptics, and of course from Labour.
Shadow chancellor Ed Balls and shadow foreign secretary Douglas Alexander used an article in The Times on Monday to demand a cut in the EU budget.
Tony Blair, who still seems to harbour some ambition to become Europe's first elected president, warned there is now a serious risk that the EU could break up.
He urged his party, and others, "not to play short-term politics with this issue" - but the temptation to do so will, needless to say, prove irresistible for some.
