I have done every test possible on this 2008 1.2 fabia no damage to vacuum pipes new seals on inlet manifold was talking to a skoda technician today he reckons timing has slipped as car wont rev could he be right ordered new timing chain kit just in case 

I don't understand why anyone would think that slipped cam timing would lead to a complete loss of manifold vacuum, in such an extreme situation the engine simply wouldn't run at all.

Presumably the engine starts and idles ok but just won't rev up and the brake pedal is solid with no vacuum assistance?

Starts but won't idle very little vacuum,read someone had same problem and it was a coil pack wouldnt  they show up on obd2 reader wouldn't they 

How do you know that there is very little vacuum, have you fitted a vacuum guage? I would first start by cranking the engine with the palm of my hand blocking the intake to the throttle body, if there is no vacuum then do a compression test & if that is OK  start searching for air leaks but you would probably hear them.

 

It is possible that the throttle butterfly is held open.

 

From memory the G65 sensor is the aircon high side pressure sensor.

Is it the 6-valve or 12-valve engine variant? If the it's the 12-valve (70bhp) and the timing chain has jumped, you've probably got valve damage too.  Compression test likely to be revealing.

Done a compression test 120 psi all three cylinders its the 12 valve engine

Did you try blocking the port on the PCV valve that goes to atmosphere?

You might need a very small finger to get over it.

 

I removed the valve and cleaned it

Try blocking that port. If it is sucking air, the PCV valve will be wide open at idle.