I am about to start a new job which had a start date on the contract of Jan 26. I then discussed this with them and I received an email from them saying that they were now happy that I start on Jan 12. As a result of this I arranged to leave my current job on Jan 9. I have now had a call saying that because their checks have not been completed I cannot start until the original date - but there were no conditions about this in the email and I will be without pay for 2 weeks if this happens.
Are they legally allowed to do this or did the email commit them to paying me from Jan 12?