THE SESSIONS (15, 93 mins) **** Starring John Hawkes, Helen Hunt, William H Macy, Moon Bloodgood, Annika Marks, Adam Arkin. Director: Ben Lewin

Once in a while, an actor delivers a performance of such raw emotional power that it’s impossible to tear your eyes from the screen.

John Hawkes, who received an Oscar nomination in 2011 for the indie drama Winter’s Bone, achieves the staggering feat in The Sessions.

In this magnificent film, he plays poet and journalist Mark O’Brien, who was paralysed from the neck down by childhood polio and required an iron lung to breathe.

Laying on gurneys and beds for almost the entire film, Hawkes effortlessly conveys his character’s maelstrom of insecurities with fearlessness and tenderness.

The Sessions begins with Mark completely reliant on his pretty nurse Amanda (Marks) to survive.

He gradually falls in love with her, only to be rebuffed – she simply doesn’t feel the same.

Amanda quits and no-nonsense Vera (Bloodgood) takes over day-to-day duties, wheeling Mark around California.

When he is asked to pen a feature on Sex And The Disabled, Mark is introduced to married sex surrogate Cheryl (Hunt), who believes she can help him overcome his self-doubt and perceived limitations during one-to-one sessions.

Cheryl slowly breaks down Mark’s defences with body awareness exercises, then builds his confidence to achieve intercourse.

An intense bond forms between the two, and after each meeting, Cheryl returns to her husband Josh (Arkin), who is completely accepting of her unusual choice of profession.

However, when Mark pens Cheryl a poem to express his deep feelings, Josh loses his veneer of cool.

The Sessions eschews smuttiness and mawkish sentiment, presenting Mark’s condition with unflinching candour.

Hawkes commands every frame. Not once does he trade on pity, allowing us to see past the physical and into Mark’s fragile, wounded heart.

Hunt bares everything for the role, delivering her best performance since As Good As It Gets, which is an apt summation for this remarkable film.