Nicolas Sarkozy and Ségolène Royal traded blows on Monday as the finalists for next Sunday’s French presidential run-off appeared ­separately – just minutes apart – on the same television programme, competing for the swing voters of the centrist François Bayrou.

For once, Mr Sarkozy seemed on the back foot. He complained bitterly about an unprecedented televised debate on Saturday between Ms Royal, the Socialist runner-up in last weekend’s first-round vote, and Mr Bayrou, the third-placed candidate of the centrist UDF party.