It follows bumper ratings for the six-part new drama, which launched on BBC One on Sunday night.
Set in and around the corridors of power, Bodyguard tells the fictional story of David Budd (Madden), a heroic but volatile war veteran now working as a Specialist Protection Officer for the Royalty and Specialist Protection Branch (RaSP) of London’s Metropolitan Police Service.
When he is assigned to protect the ambitious and powerful Home Secretary Julia Montague (Hawes), Budd finds himself torn between his duty and his beliefs. Responsible for her safety, could he become her biggest threat?
Bodyguard is written by Jed Mercurio and made by World Productions for BBC One. The six-part series also stars Gina McKee, Sophie Rundle, Pippa Haywood, Stuart Bowman, Vincent Franklin, Ash Tandon, and Nina Toussaint-White.
The opening instalment had 6.7 million viewers while episode two on Monday dropped only slightly to 6.4 million.
Now writer Jed Mercurio has revealed hopes of a second season.
He made the comment on Twitter in a message to former Home Secretary Amber Rudd, who had written an opinion piece on the series.
Mercurio wrote: "Thanks to @AmberRuddHR for an interesting and thought provoking article on #Bodyguard."
He added: "Maybe she'll honour us with a cameo appearance if we get a second series!"
For now, the first series continues with episode 3 on Sunday 2 September at 9PM on BBC One.