The Taoiseach has rejected further calls for the Russian ambassador to Ireland to be expelled.
Micheal Martin refused to bow from pressure opposition parties in the Dail on Wednesday, as Sinn Fein and Labour pressed the Government to expel Yury Filatov.
Both parties acknowledged there were "valid" reasons for keeping the ambassador in the country, but said they paled in the face of the horrors being perpetrated in Ukraine.
Sinn Fein leader Mary Lou McDonald, who spoke of the "harrowing scenes emanating from Ukraine", called on Ireland to take the lead in Europe's diplomatic response to the Russian invasion.
"Every diplomatic avenue must be used to end the war. All diplomatic leverage must be employed.
"It's clear that the actions of Russia in Ukraine are abhorrent. And to that end, I want to ask you about the expulsion of the Russian ambassador to Ireland.
"I happen to believe that now is the time for our Government, for you as head of Government, to take the lead on this issue.
"I invite you as head of the Irish Government to lead again, to lead together with our partners in Europe and to leverage this crucial diplomatic tool.
"It is essential, as shells rain down on Kyiv, as people flee for their lives, that we demonstrate in every way to the Russian Federation that our island means business and state we will not offer any shelter, any excuse, any cover in any form."
Labour leader Alan Kelly questioned the logic of retaining an ambassador accused of being a proven liar.
"We have always shown leadership in this country and the Russian ambassador is a liar. He lied to the Irish people on multiple occasions.
"We are in unprecedented territory, with a regime that is acting in an absolutely horrendous way.
"What is the point of having diplomatic channels with somebody who lies? You can't trust them. If he had said nothing, it would have been better.
"I am asking you formally to withdraw our ambassador from Russia, because I believe we have to do that."
Mr Martin in recent days has stressed the importance of maintaining diplomatic links to Moscow, even in the face of scepticism from within his own party.
On Wednesday, he repeated the importance of keeping a channel to Russia amid the uncertainty of the weeks to come.
He also rejected the suggestion by Sinn Fein that a charge d'affaires could be appointed to keep some diplomatic link to Russia.
"We're less than a week into this horrific war against the Ukrainian people. I think President Putin has not achieved the rapid victory over the Ukrainian people that he anticipated.
"It's very clear now that President Putin is moving into a new phase where you're witnessing extreme forms of barbarity, in terms of barbaric attacks on cities, on civilian targets, levelling cities, and it's quite horrific."
Mr Martin said Europe could see a humanitarian crisis of an unparalleled scale.
"We as a country have to now get our heads around that and start preparing in relation to the humanitarian responses that potentially will be required to deal with the scale of migration caused by the war itself.
"I think the Irish people will do the right thing. We will not be found wanting in relation to our humanitarian response."
He said diplomatic expulsions were the "easy bit" but it was more important for Ireland to act "in concert" with the EU.
Responding to Sinn Fein, Mr Martin said: "We've expelled diplomats in the past. You would not have found favour with that in the past, as you know, and you took a view that it was contrary to military neutrality at a time in the teeth of Russian aggression.
"I would readily acknowledge that when that happens, there is a reciprocal response. And you end up with nobody on the ground in Moscow, where we do have Irish citizens."
He told Mr Kelly the sanctions imposed by the EU so far were more significant than expelling ambassadors.
"I don't accept the basic premise that's been articulated here this morning, that Europe should split in different directions. Europe should stay solidly united."
Mr Martin and Mr Kelly clashed as the Labour leader also pressed the Government to take further action on corrupt money from Russia moving through Ireland, with the Ceann Comhairle forced to intervene to call for silence.
The Taoiseach said: "This shouldn't be an issue of division. We should be united in this house.
"We are getting calls from deputies and senators across the house, legitimate calls, about helping our citizens in Ukraine and elsewhere. We're getting very legitimate calls that we're responding to and we're working with people.
"I'm just simply saying you know this and on a better day and on a different day, you would agree with me, deputy. I regret to some extent the attempts to divide a house on this and I think that's wrong."
Meanwhile, members of the Ukrainians In Ireland and Uplift Ireland campaign groups staged a protest on Wednesday outside the European headquarters of Facebook and Google in Dublin.
Layla Wade, campaigner with Uplift, said: "We are supporting the call from the Ukrainians in Ireland group to urge Facebook and Google to remove all Russian state-backed propaganda accounts from their platforms.
"The Kremlin state has been waging an information war for years and allowed their audience on their accounts to grow to such high numbers and we are here to call on social media platforms to stem that from happening.
"This has been happening for years and it has reached an acute stage which is what we are seeing happen to the people of Ukraine, and it is based on an information war as well as what is happening on the ground.
"Ireland is the European home, and in some cases international home, for some of these social media companies and we are here to call them to remove the accounts.
"They have come out with announcements saying they would remove the accounts on an EU-wide basis, but we know that social media has no borders and we are calling for a removal on a world-wide basis."
