I am a tenant in a property with a private driveway. on the driveway is a concrete man hole cover. i

I am a tenant in a property with a private driveway. On the driveway is a concrete man hole cover. I have driven over this many times in the last 4 years without a problem until now and my cars front wheel went through it, broke it and damaged my car. Who is to blame? surely it is down to the landlord as it is on the driveway? they are trying to blame me. Please advise?

The question is who did, or failed to do, something that caused the cover to break. If it failed from normal wear and tear, that's the landlord's problem. If they have proof that it was the result of something you did beyond driving over what was put there to drive over, they have no reason to blame you for it.

Unless you have evidence that the landlord knew the cover was defective and failed to fix it, you have no reason to blame him/her for the damage to your car either. If you have comprehensive insurance on your car it should cover the damage to the wheel.