(1) Section 811 of the Principal Act is amended by inserting the following after subsection (5):

"(5A)

(a) In this subsection -

'assessment' includes a first assessment, an additional assessment, an additional first assessment and an estimate or estimation;

'amendment', in relation to an assessment, includes the adjustment, alteration or correction of the assessment.

(b) Where the opinion of the Revenue Commissioners, that a transaction is a tax avoidance transaction, becomes final and conclusive, then for the purposes of giving effect to this section, any time limit provided for by Part 41, or by any other provision of the Acts, on the making or amendment of an assessment or on the requirement or liability of a person to pay tax or to pay additional tax -

(i) shall not apply, and

(ii) shall not affect the collection and recovery of any amount of tax or additional tax that becomes due and payable.".

(2)