FRENCH President François Hollande is under pressure to clarify his personal situation after a magazine alleged he was having an affair.

Hollande, 59, has threatened to sue French Closer magazine over the claims of a secret relationship with actress Julia Gayet, 41, but did not deny the allegations.

He said it was an "attack on the right to privacy" but one French newspaper said the scandal would be catastrophic for Hollande's credibility.

The controversy is expected to overshadow a major press conference this week outlining the economic programme for the year ahead.