Labour's Pat Rabbitte, the PDs' Michael McDowell, Trevor Sargent of the Greens and SF's Gerry Adams squared off in the Prime Time Leaders' Debate at RTÉ studios tonight..

The one-hour verbal spar moderated by Prime Time presenter Mark Little helped define the policies and personalities of the possible coalition partners for Fianna Fáil or Fine Gael.

Their leaders, Bertie Ahern and Enda Kenny, will debate for 80 minutes tomorrow night.

While Michael McDowell and Pat Rabbitte managed to exchange pithy one-liners, issues like taxes, health, policing and immigration prompted heated debate among the four men.

Labour leader Pat Rabbitte renewed his stance that his party would not enter into a coalition with Fianna Fáil, while Green leader Trevor Sargent asserted his party's independence.

After Gerry Adams brought up the subject of drugs during the crime portion of the debate, Michael McDowell said Mr Adams 'sold provo know-how to the FARC guerillas in Colombia in exchange for 25 million US dollars.'

Mr Adams responded: 'That remark is proof that you're not worthy to be Minister of Justice'.

For analysis of the debate, listen to Morning Ireland from 7-9am on RTÉ Radio One. For Ireland's most comprehensive election coverage, bookmark RTÉ.ie/election.