[1][2][3] Clerc was left out of the French squad for the 2006 Autumn Internationals, but was called up as a replacement for Cédric Heymans for the match against Ireland during the 2007 Six Nations Championship.

[4] In a closely contested match at Croke Park, Clerc scored a last-gasp try to snatch a 20–17 victory for France.

In a post-match interview after the match against Ireland Clerc stated to the French TV channel France 2 that he "never would have been able to score a hat-trick if Shane Horgan had been playing."

During the 2008 6 Nations, media attention focused on the final match of the tournament, where Clerc and Shane Williams would play as opposite numbers.

Clerc ruptured the ligaments in his left knee while playing for Stade Toulousain against ASM Clermont Auvergne in April 2008.

On November 17, 2012, against Argentina in Lille, Clerc scored two tries to take his overall international tally to 34 tries, overtaking Philippe Saint-André to become France's second highest try scorer.