Minister for Defence Willie O'Dea has questioned figures that Fine Gael says will provide for an additional 2,000 Garda recruits.
Mr O'Dea claimed Fine Gael had promised 2,000 extra gardaí but had only budgeted enough money to pay for an extra 1,000.
Calling on Fine Gael to explain the differential, Mr O'Dea said the promise was "a fundamental part of Enda Kenny's contract, and it doesn't stand up to even the most basic scrutiny."
The Minister claimed Fine Gael's contract was "nothing less than a con trick which is deliberately dishonest." He insisted it could not be delivered "even by the most benign interpretation of their figures".
Mr O'Dea said Fianna Fáil would provide funding if re-elected for 2,000 more gardaí above the funding already provided.