The Aontú leader Peadar Tóibín is accusing Sinn Féin of targeting his seat in the upcoming general election.
The Meath West TD left the party in 2018 following a row after being suspended for voting against abortion legislation in the Dáil.
He subsequently established Aontú, and is currently the party's only sitting TD.
Aontú are now seeking three or four seats in the upcoming General Election, Tóibín says. including retaining his seat in Meath West.
However, the party leader says his constituency is now receiving particular attention from his former party
"It's been specifically targeted with large resources now from Fine Gael and Sinn Féin," he claimed.
"I reckon that Mary Lou (McDonald) will have a Navan accent by the time the election is over, she'll have been in the constituency so much," he added.
But speaking at the launch of Sinn Féin's housing policy in Dublin this afternoon, Eoin Ó Broin defended his party leader.
"She has been in my constituency, she has been in Louise O'Reilly's constituency, Aengus Ó Snodaigh's constituency - that's what leaders do.
"Given the levels of homelessness in the State, given the chronic levels of housing need, I would have thought Peadar would be talking more about those issues and not people's accents," he said.