HELP! Offer retracted the day before start date

[RMC1986]

Hi,

Looking for advice. I was on the waiting list, and contacted with an offer a few weeks ago. I sent all the paperwork off, and the stuff for the security checks. I declared on my application that I had a couple of driving convictions, but was told I had passed and offered the job anyway.
When my DBS came back, these driving offences came up as expected. I contacted the HR and double checked on Tuesday that this was OK, and she said she couldn't see there being a problem. I had declared them, she had my details in front of her.

I was given my start date about 11 days ago (before the checks were complete) and the offer letter. That was supposed to be tomorrow. I handed my notice in last week, as I had to give a week's notice and I was due to start my training tomorrow. I have then had an email today to say I have failed the checks on the basis of one of these driving offences that I declared from the outset. So I now have no job! Is this normal? Is there anything I can do?

Surely, they can't offer a job and start date, and then retract the offer the day before I was due to start on the basis of a driving conviction I disclosed on my initial application back in January?

Help!