Éamon Ó Cuív, the Minister for Social Protection and grandson of Fianna Fáil founder Eamon de Valera, has received a letter asking him to donate money to Fine Gael.
Purporting to be from Fine Gael leader Enda Kenny, the letter was accompanied with an envelope for Ó Cuív to put a donation in and send it back to Kenny.
The letter displaying a photo of Kenny and pictures of the Fine Gael members of Castlebar Town Council and Mayo County Council was titled a "Message to local constituents from Enda Kenny".
It is understood that somebody in Mayo received a genuine letter from Kenny in recent weeks and decided to play a practical joke by forwarding it on to Ó Cuív at his home address in Connemara.
Ó Cuív is said to have seen the funny side of the prank and his spokeswoman said that while he found the letter "amusing", he would not be making any comment about it.