An immediate review of politicians' security is needed in the wake of Sir David Amess's killing, the Taoiseach has said.
Micheál Martin, who revealed his own home has been targeted in the past and people have "roared and screamed" in his face while in public, said there is a need to assess the physical security of TDs.
Gardaí have also been called to the home of Tánaiste Leo Varadkar after a number of people staged a protest outside.
The killing of the British MP has intensified concerns of TDs and ministers carrying out aspects of their job in public.
Mr Martin also highlighted the targeting of politicians on social media, saying groups are formed to "create bile" against elected representatives.
He said: "In all matters to do with security and policing, I think intelligence is the key ingredient and is the key prevention factor.
"It's a very positive feature of Irish politics and we have to protect that.
"I think it's through the intelligence network and the intelligence capacity of An Garda Síochána and others, that's the ultimate protection that we can give to politicians, to spot things before they become challenging and difficult.
"There are difficulties. I think the online hate messaging - groups are forming who create bile around politicians and target politicians and target others as well, I think that's not acceptable either. On the physical security side we have to keep an eye on it."
He added that gardaí have a role to play in monitoring extreme groups.
"I think we do need to review it in terms of what security is required," Mr Martin said.
"I think intelligence, networking, what I mean by that is people keeping a very sharp eye on it and gardaí are well placed to do that and they have an idea of what's happening in different extreme groups and people who are being harassed.
"We've all experienced that, and I've had many protests.
"I've never made a big deal about it but there have been protests, they haven't been violent, but there have been protests outside one's home.
"I would say we need to protect that ingredient in Irish politics, that connection between people. Sometimes I think some extreme political groups want to disrupt that connection. That's part of the agenda."
Mr Martin said he has been targeted while out walking.
"I think it's absolutely essential that we don't lose the ground, and don't lose the street as elected representatives. I'm a passionate believer in parliamentary democracy.
"There's an agenda there sometimes to disrupt that sort of practice, to almost denormalise conventional politicians, and to turn people against them, and that then in itself can generate a more violent interaction with politicians which has to be condemned and people need to pull back from."