Army and gardai have been called following a bomb scare at the constituency office of the Republic's Environment Minister Alan Kelly on Friday morning.
A female staff member alerted the gardai after opening a package which contained a suspicious substance.
The package reportedly contained a sinister threat to the life of the Labour Party politician.
The staff member was left extremely shaken after opening the package.
The Gardaí took the decision to call in the defence forces as a precaution.
There have been a number of sinister threats made against Mr Kelly in recent months.
A garda spokesperson said the offices in Nenagh, Tipperary are temporarily closed.
"Gardai and members of the army bomb disposal squad are currently at the scene and investigations into the threat have begun," the spokesperson said.