French jets have conducted between a fifth and a quarter of daily sorties, while the British have taken part in one in 10 missions, a NATO diplomat said.

The head of the Royal Air Force (RAF), Air Chief Marshal Stephen Dalton, told The Guardian newspaper that British warplanes are likely to play a role in the no-fly zone over Libya for at least six months.

The five other nations participating in bombing missions — Belgium, Canada, Denmark, Italy and Norway — use around 30 warplanes in total.