But, while the odds may be stacked heavily against the Republic, skipper Keane remains convinced their destiny is in their own hands.

He said: “As a team, we know exactly what we have to do – we have to go out tomorrow and perform and make sure we have got no regrets.

“Overall, in the campaign itself, we haven’t lost away from home and that has given us a lot of confidence.

“The manager has instilled that into us because the performances away from home have certainly been good and that’s something we can take into tomorrow also.

“It has been a decent campaign for us – but it will mean nothing if we don’t produce tonight.

“We are in this campaign to be at the World Cup and tonight will decide it.”

Ireland have won only one of the previous five play-offs in which they have been involved over the years and the fact no side has ever reached the World Cup finals after losing the first leg does not bode well.

However, Keane is confident the final 90 minutes of the qualifying campaign - it could yet be 120 – might just produce a major surprise.

He said: “We know exactly our job that we have to do and, if we don’t do our job, we won’t be going to the World Cup, it’s as simple as that.

“By no means is it going to be easy but I certainly believe, with this squad of players we have, there is certainly a twist in this game, there’s no question about that.”

As if there was not already enough at stake, Lassana Diarra’s final whistle broadside at Croke Park raised Irish hackles and, while both manager Giovanni Trapattoni and Keane are confident there will be no loss of discipline in Paris, the midfielder’s comments have added further spice.

Keane said: “It’s obviously put a bit of fuel to the fire but we can’t be going into the game thinking about Diarra or the comments he made.

“We have to concentrate on the job at hand and we will certainly be doing that.”