Updated April 22, 2017 05:30:59

Photo: One policeman was killed and another two wounded in a shooting incident in Paris ahead of the presidential election. (Reuters: Christian Hartmann)

France is at the business end of one of the most dramatic and divisive presidential elections in its modern history.

The attack that has left one police officer dead and another two wounded occurred at the same time the final TV debate was taking place and is likely to see the final day of campaigning suspended.

The timing means it could have an impact on how people vote when they go to the ballot box for the first round of the election this weekend.

But it is just impossible for anyone to accurately forecast what that impact could be.

Terrorism has already been a major issue in the campaign and some feared an attack like this would happen.

Far-right National Front Leader Marine Le Pen and centre-right Republicans candidate Francois Fillon have been campaigning hard on boosting security agencies and stopping terrorism.

They have claimed it is a weakness of the supposed presidential favourite, the centrist Emmanuel Macron and far-left insurgent Jean-Luc Melenchon.

The polls are so close that all four have a reasonable chance of finishing in the top two this weekend and making it through to the final run off in a fortnight.

But it is important to point out that voter disillusionment is so high in France that as many as a third of people may not vote.

Turnout is likely to be a major factor, so even something as unremarkable as the weather could have a significant impact on this campaign.

This attack will devastate Paris and it is one more unpredictable element in an already unpredictable campaign.

Topics: terrorism, world-politics, france

First posted April 21, 2017 09:18:15