Sinn Féin's deputy leader says she's not concerned by stagnant poll numbers for the party.

Support for Sinn Féin was unchanged at 19% in the latest Red C poll for the Sunday Business Post, behind Fine Gael on 29% and ahead of Fianna Fáil on 17%. Labour rose to 10% and Independents and Others stood at 25%.

Sinn Féin's Mary Lou McDonald says she's not worried about closing the gap on Fine Gael with just weeks to go until the General Election.

She says she doesn't believe support for the party has reached a ceiling.