Once you have decided that a nomination is valid, it cannot be challenged during the election, although it may be challenged after the election by way of an election petition.1
If you have made a formal determination but then, as a result of an objection, later decide that the nomination form should in fact have been determined as invalid, you can make a further determination to this effect.
If a nomination form is determined to be invalid you must:2
state that fact on the nomination form,
write on it the reasons for rejection on the form
sign the form
In both cases you must send notice of the decision that a nomination form is valid or invalid to each candidate at their home address.3
This should be done as soon as practicable after your decision has been made.