In reckoning any period of time for the purpose of any applicable limitation period in relation to a relevant claim (including any limitation period under the Statute of Limitations, 1957, section 9(2) of the Civil Liability Act 1961, the Statute of Limitations (Amendment) Act, 1991 and an international agreement or convention by which the State is bound) -

(a) the period beginning on the making of an application under section 11 in relation to the claim and ending 6 months from the date of issue of an authorisation under, as appropriate, section 14, 17, 32, 36, 49 or 49A shall be disregarded insofar as it relates to one or more respondents named at the time of the application made under section 11, or

(b) the period beginning on the addition of a further respondent or respondents in relation to the claim and ending 6 months from the date of issue of an authorisation under, as appropriate, section 14, 17, 32, 36, 49 or 49A or rules under section 46(3)(b) shall be disregarded insofar as it relates to such further respondent or respondents.