There solicitor saying you could not enter on safety is total Cr**p.
Assuming you have gas connnected to property my story is i was rang by a passer by saying they could smell gas (they saw your number on the let board) you then went down to property as a precaution (You have a right to enter the property).
Thats your story for gaining entry.There Quiet enjoyment comes second to the house and street being blown up.
On entry you found no smell:
You did notice the scales & safes so you did your public duty and called the police.
The tenant also lied from the outset Re:Benefits.
So they in effect took up tenancy under false pretences which invalidates the tenancy agreement.
I would follow the advice of landlord action & also join the
NLA.
Can you imagine the judges reaction if there was indeed a gas problem
:Judge the solicitor told me i could not enter the property even under on the safety issue:
Stick with the people who deal with these issues day in and day out.
Hope this helps
Regards
Les