How can I fix my immobilised MK5 Ford Escort?

I have a Mk 5 Ford Escort I changed the ignition barrel but forgot to change the microchip in the key when taking the battery out to charge it. I had the new key in the ignition when I tried to start the key the next time, when the battery was charged. It obviously wouldn't start so I changed the microchip in the key to the original, but the car just turns over with no spark the car is immobilised.
How can I get my immobilise my MK5 Ford Escort to start?