Mary Lou McDonald has said it's now “obvious” that Sinn Féin ran “too many candidates” in the local elections.
Her party has elected 96 councillors after 906 seats have been filled.
Meanwhile, Fine Gael and Fianna Fail are both tied with 232 seats returned each.
Deputy McDonald said she was disappointed with the results.
“We ran a great, talented slate of people and wanted to give everyone the opportunity to vote for Sinn Féin across all the local election areas,” she said.
“Our candidates were fantastic and worked really, really hard.
“I am really disappointed that we didn’t get more of them over the line.”
Sinn Féin in Europe
Elsewhere, in Dublin’s European election race, Sinn Féin’s candidate Lynn Boylan expects a long counting process ahead.
“I love counts, but it’s always nicer when you’re not the candidate,” she said.
“It’s great to see the democratic process in action; we’re very transparent in Ireland how it works.
“But it's long waits and I have my knitting with me, so I’ll be occupying myself that way to try and stay off the phone.”
Senator Boylan, who is currently placing third with 36,980 votes after count 11, said social media is creating false narratives in Ireland.
“The online world is a fake world; do you know what I mean?
“Most people you meet on the doors are very polite, very friendly, very warm; the Irish people are very generous.
“They want to engage in conversations they want to hear about policy and discuss concerns they might have.
“What you see on social media is a completely false narrative that’s out there.”
Main image: Mary Lou McDonald at the RDS following a disappointing local election, 09/06/2024. Photograph: Sasko Lazarov / © RollingNews.ie