Stewart Dickson MLA was speaking after a shotgun cartridge was discovered tied to the lock of his Carrickfergus constituency office on Friday morning.
This latest incident comes a week after a hoax device was discovered outside the Alliance Party’s constituency office in East Belfast.
Mr Dickson said: “This is yet another senseless attack on the hardworking Alliance team in East Antrim and the local community, many of whom rely on the constituency services that we provide.
“There is absolutely no justification for this level of intimidation and there should be no place in our society for those who wish to spread fear and intimidation.
“Those behind this unjustifiable attack do not speak for the majority of residents in East Antrim, who want to see a peaceful future for our area and Northern Ireland as a whole.
“Clearly there are those among us who want to drag us back to the dark days of the past and I would appeal to anyone with information to contact the PSNI.
“The perpetrators of these acts are obviously threatened by the non-violent, non-sectarian and progressive message of the Alliance Party. This latest attempt to intimidate us only highlights their wish to disrupt the good work of Alliance Party representatives who are working to deliver the shared and better future that everyone in our area deserves.”