The duo's partnership is due to hit a big obstacle in the coming days when Shirley learns of Phil's (Steve McFadden) affair with Glenda (Glynis Barber), leaving fans to wonder whether she will still go ahead with her plans to marry him.
Offering her take on their romance, Henry told Inside Soap: "Phil and Shirley are definitely a perfect match - they work well together. Shirley really stood by Phil and pulled him back from the brink of his drug addiction, when he hit rock bottom. The fact that they could get past that means they have a strong relationship.
"I think it would need lots of effort to make it work and they'll never have the perfect relationship. But neither Phil nor Shirley are ones for the quiet life, so who knows what will happen?"
Asked whether Shirley would stay with Phil just to keep a roof over her head, the actress replied: "She's a strong, proud woman - and she wouldn't stay with someone for those reasons. Right now, though, Shirley's in shock - she needs time for the reality of what she's discovered to sink in."
Shirley discovers the truth about Phil and Glenda next Monday at 8pm on BBC One.
> 'Enders Pics: Phil and Shirley promo shots
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