Identical twins are only "identical" because of genetics and we human's can't tell them apart. In actual fact, identical twins are not identical due to enviromental factors caused by the fact they are two seperate people.
As a result, the facial recognition software should find sufficient differences between the two twins to distinuish between them.
If the sftware can't, then it sucks and Fujitsu should get new software.

Just 1 word...

TWINS

I dont know if Manchesters BAA and a compulsory shopping centre like the hell hole london airports but if they want to make life easier for the passenger they could revert to being an airport.
Real security checks aside theres no reason to be at the airport two or three hours before a one hour flight.
Its quicker to walk to Paris these days.

"inconveniencing"?

Are you running for president of something?

Yeah and if you are a wanted terrorist you can just use a burka and walk on through, so it's not inconveniencing anybody really eh.