Gay prisoners will be allowed to tie the knot inside some of the country's toughest jails.

Top security lock-ups like will have to host civil partnership ceremonies, provided the inmates fund the nuptials themselves.

The green light for killers, rapists, drug dealers and terrorists to get hitched inside prison was given after a homosexual crook's mum wrote to inmate magazine Inside Time to get the go-ahead.

'My son is currently held as a Category A prisoner and has expressed a wish to "marry" (in a civil ceremony) another male Category A prisoner who is in the same jail,' the concerned woman wrote.