Anthony Bamford gets seat in House of Lords where he can create and amend new laws.
The billionaire JCB boss and his family are among the biggest Tory donors.
Bamford headed a list of cronies handed peerages by the PM last summer.
It was reported he had been previously rejected thanks to concerns over his tax affairs. He was caught up in a row when he was among wealthy backers at a “thank you” dinner in No10.
Mr Cameron was accused of rewarding him with high-profile factory visits.