After exporting the ad and uploading to google Adwords the ad was successfully approved and the preview worked exactly how we wanted it to.
As a final test we tried the ad in a live environment but found that the iFrame was not present. Has anybody come across this strange issue ?
I have attached a screenshot of advert in its live environment with the iframe missing.
I have been in touch with the Google Adwords team who forwarded me to this forum.