You see that to accept flights etc for political campainging is quite wrong, what with the targetted officials being civil servants an all.
So wrong indeed that Farage has written to all the institutions on the offer,
"Staff Regulations of Officials and the Conditions of Employment of Other Servants of the European Economic Community and the European Atomic Energy Community
RIGHTS AND OBLIGATIONS OF OFFICIALS
An official shall carry out his duties and conduct himself solely with the interests of the Communities in mind; he shall neither seek nor take instructions from any government, authority, organization or person outside his institution... (my emphasis)
An official shall not without the permission of the appointing authority accept from any government or from any other source outside the institution to which he belongs any honour, decoration, favour, gift or payment of any kind whatever, (my emphasis)
An official shall refrain from any action or behaviour which might reflect
adversely upon his position.
Which can be found here
It is apparent to me that any official of the European Communities availing him or herself of this offer, would firstly be accepting, from another source a "gift or payment of any kind whatever" viz, a return flight to Dublin. They would also would by accepting the condition, "You must agree in writing to canvass for a Yes vote while in Dublin" be in clear breach of Article 11, "or take instructions".
To do either would, in an impartial, honest and transparent civil service mean that they clearly breach Article 12, as their behaviour would clearly "reflect adversely upon his position".
Farage goes on to demand action,
To that end, I request and require that you immediately send a message to all members of staff of the European Parliament warning them that to take up this offer would result in a breach of the Staff Regulations and thus a disciplinary procedure.
So either they ban them from taking part, or don't. If they don't that is either negligence (the offer only comes into force on Monday) or they grant officials permission. Which in itself would rather show the Irish people what they are up against in the EU.
By their deeds we shall know them.