Is it true that in the light of certain allegations, which I'm sure are false
The allegations are not false, or at least the allegations, as presented, are not disputed.
Bertie was given about 50K by some friends, who also happened to be prominent businessmen, which was presented as a loan, when Bertie was short a few quid after his seperation. When Bertie attempted to pay it back they said not to bother. No gift tax was paid. One of the donations was made on a corporate NCB stockbrokers cheque, a company that would be quite sensitive to decisions made by the Minister of Finance at the time. At least 4 of these prominent businessmen have been given lucrative directorships on state boards, although there is no particular reason to relate this with the donations, rather their friendship with Bertie. The loan plus interest was paid back in the last few days to the people involved who donated it to Bertie's ex-wife's favourite charity.
It is not disputed that these people genuinely were friends, nor are their motives disputed.
Bertie also decided to give a dinner speech in Manchester when Minister of Finance. His attendance was wholly reliant on him being Minister of Finance. No fee was paid, however guests at the dinner were asked to contribute to a voluntary whip round which Bertie graciously accepted - I can't remember the amount involved £18k, I think.
Nobody is alleging there was anything illegal in what Bertie has done. The appropriatness of the actions of a Minister of Finance is more the question, although the revenue commissioners would appear to have a case worth investigating.
My personal view is that these actions alone would not justify resignation. A scruffy, embarrassing mess which justified some explanation but that is it. Having said that, I trust his integrity (even) less, and would love to see a full formal investigation into all his financial dealings in the last 20 years. Somehow I can't see that happening.