Bertie Ahern does not always respond well to criticism. In a 2009 interview he suggested that anyone who blamed Fianna Fail for Ireland's economic crisis should "dig the garden or grow bluebells or do something useful".
The ex-taoiseach went on to slam "cynics and knockers, people who always see the glass as half-empty. I can't understand people who are always bitching, saying, 'It's the Government's fault, it's the doctor's fault, it's the cat's fault'. It's everybody's fault except their own".
To put it politely, Bertie will have to come up with something a bit better than that when he appears at the Oireachtas banking inquiry on Thursday. Nobody will be watching more anxiously than Fianna Fail leader Micheal Martin.
performance
True, Ahern's relationship with the Soldiers of Destiny is so bad these days that he no longer holds a membership card - but a dodgy performance could still do his old party serious damage as the general election looms into view.
For the banking inquiry itself, this must be their juiciest political target yet. While Bertie left office more than a year before Ireland's financial collapse, it is widely believed that his governments' reckless overspending laid most of the groundwork.
The committee members struggled badly to land any punches on Brian Cowen or Charlie McCreevy - but if they cannot give Ahern a rough ride, they might as well pack up and go home.
Yesterday's advance reports of Bertie's testimony have done nothing to ease Fianna Fail nerves.
He reportedly plans to express his regret for the pain suffered by ordinary people, but will go on to insist that we are still better off thanks to his Celtic Tiger policies.
He is also expected to spread the blame as thinly as possible between banks, regulators and international agencies.
If this is the gist of Bertie's evidence, Micheal Martin will be left clutching his head in despair. Ever since he took over Fianna Fail in 2011, Martin has tried to project the image of a party that knows it screwed up and is deeply sorry for the mistakes it made.
The last thing he needs is a reminder of the Fianna Fail that so many voters came to despise - arrogant, incompetent and fatally out of touch.
There is another good reason for Micheal to bite his nails about Bertie's return to Leinster House on Thursday. Ahern is highly skilled at delivering soundbites, not so good in long conversations that require him to think on his feet.
As Taoiseach, he communicated largely through brief doorstep interviews that allowed him to get his message across without facing too many awkward questions.
In other words, a day-long grilling from TDs and Senators is exactly the sort of forum most likely to trip Ahern up. Forensic questioning often provoked him to make verbal gaffes known as 'Bertie-speak', such as the occasions when he asked people not to "upset the apple tart" or "stop throwing white elephants and red herrings at each other".
destroyed
More seriously, it prompted him to tell the Mahon Tribunal that some of the money mysteriously sloshing through his bank accounts had been won on the horses - a terrible moment that in many people's eyes destroyed his credibility once and for all.
Of course, Bertie's strange use of the English language can sometimes be an advantage. The Socialist Party leader Joe Higgins once complained that asking him questions was "like playing handball against a haystack - there is a dull thud but nothing comes back".
He is quite capable of pulling out a performance that bears out Charlie Haughey's description of him as "the most skilful, most devious, most cunning of them all".
For now, Micheal Martin can only watch and hope. Bertie Ahern is on record as saying that he doesn't "think much" of the current Fianna Fail leader.
How fitting it would be if his banking inquiry evidence destroyed Micheal's chances of becoming Taoiseach once and for all.