1. New drink driving limit

This could be the straw that breaks the camel's back. A number of backbench Fianna Fáil TDs have said that they will walk from the party if the Minister for Transport, Noel Dempsey, forges ahead with his plans to lower the blood alcohol limit from 80mg of alcohol per 100ml of blood to 50mg. Dempsey plans to force through the new legislation in his Road Traffic Bill in the current Dáil session and backbenchers are infuriated. Watch this space.

2. Another medical card fiasco

Ernest Blythe did it in the 1920s when he reduced the old age pension. Richie Ryan was dubbed 'Richie Ruin' for his tough 1970s budgets. John Bruton was pilloried for his VAT on children's shoes. Brian Lenihan (below) joined this infamous list last October when he announced that the government was going to withdraw the universal right of over-70s to have a free medical card.

Lenihan is widely regarded for being on top of his brief by now but he cannot afford to let another medical card fiasco develop after his 9 December budget.

3. Public Sector pay

Many respected economists and bodies such as the ESRI are all saying that public sector pay rates need to be cut. Looking at the country's balance sheet, it is hard to argue with them. The reality for backbenchers is that they will have to face the wrath of organisations such as the new 24/7 Frontline Services Alliance, which represents gardaí, prison officers, nurses, soldiers and other public servants who provide round-the-clock coverage. This body has held regional meetings across the country and if this vocal demographic feel aggrieved by the budget, the pressure may be too much for some backbenchers.

4. Social welfare cuts

Conventional wisdom in government circles suggests that it is not a question of whether there will be social welfare cuts on 9 December, but a question of how much will be cut? Lenihan has to strike the correct balance between making the necessary changes in this highly sensitive area, yet not leading to a situation where the most vulnerable people in the country are protesting outside Leinster House. Draconian cuts in this area, and implementation of other elements of Colm McCarthy's Bord Snip Nua report, could force 'windy' backbenchers to jump ship. Backbenchers are also adamant that the old age pension is "sacrosanct".

5. Crisis? Which crisis?

The phrase 'Crisis? What crisis?" was coined 30 years ago, during Britain's winter of discontent in 1979 when Jim Callaghan was Prime Minister. The current government is one of the most unpopular in the history of the state. And the term, 'Crisis? Which crisis?' might best describe its tenure in charge. Former taoiseach Albert Reynolds famously said that it is "the little things" that trip up a government in the end. So who knows which crisis, however big or innocuous, could begin this government's end of days.