sorry to do this but we must now run through the "idiots checklist"...
is the switch for the loft lights switched on when you test the downlight?
is there another switch other than the one in the hallway?
is there a fused switched spur in the loft? is the fuse in it blown?
is the power back on when you test?
you will need to aquire a multimeter in the morning and use it's AC volts range to check if there is 240V at the terminal block when the power is on, and the switch itself is on..
thanks everyone for their help much appreciated
the light works now solved the problem
now comes the silly bit on my behalf explaining to u all what the problem was but i feel i have to admit my error to u all
as i wasnt getting a response to my ? about how i wired the temp wiring for downlight i took it as read that that wiring was ok
so the fault must b in the other cable \switch as col was trying to determine .
so i took the step of connecting a temp cable from the downlight to the other terminal on the switch which worked
so the set up was correct therefore must be the permanent cable
i then checked the connection in the terminal block and found the bare wire had bent somehow and i was only tightnen the red insulation so no connection
i spoz these things happen
but again thanks all for your time n patience
alternatively, if you live close by I could swing by and take a look for you.. minimum charge £20