please give advice

[peter786]

hi
An illegal enters in this country and lives here without a status.
He gets married with a British girl and after 2-3 months they get separated and eventually divorced later on the girl gives birth to a child and the court gives accession right to the father and he meets with his son every week.

This person has applied to the home office for a stay to access his child.
Home office has written that his application is valid and they are considering it.

being an illegal entrant what are his chances of getting this.
Any suggestions?/