The film stars Gemma Arterton, Sam Claflin, Bill Nighy, Jack Huston, Jake Lacy, Richard E. Grant, Henry Goodman, Rachael Stirling, Eddie Marsan, Helen McCrory, and Claudia Jessie.

The British government is desperately seeking to shore up the morale of the general population, and is pursuing a long strategy of getting the US to join the war and defeat Hitler.

They tell her that they never reached Dunkirk because their boat broke down, although they did take on soldiers from an over-crowded tug returning the other way, causing newspaper reporters to believe they had come from the combat zone.

Discussing the difference between reality and fiction, Buckley recalls how the First World War broke his father's spirit, and argues that stories help people by giving them a sense of structure and closure.

The extra work means Catrin misses the opening of Ellis's exhibition and must rush back to London to catch its final day.

Back in London, the film's American distributors demand an ending with more "oomph", but Buckley is in a romantic funk and fails to write anything satisfactory.

[4] On 10 September 2015 Jack Huston and Jake Lacy joined the film along with Richard E. Grant, Helen McCrory, Eddie Marsan, Rachael Stirling, and Henry Goodman.

[7] Locations used included: in Pembrokeshire, Freshwater West beach - which stood in for Dunkirk - Porthgain harbour, the Trecwn valley, and the Cresselly Arms at Cresswell Quay; in Swansea, the Guildhall and Grand Theatre; and in London, Bedford Square in Bloomsbury.

The site's critical consensus reads, "Carried along by a winning performance from Gemma Arterton, Their Finest smoothly combines comedy and wartime drama to crowd-pleasing effect.

[20] Peter Bradshaw of The Guardian called the character of Hilliard "a colossally proportioned scene-stealer" and wrote that "Arterton brings a rather beautiful kind of restraint to her role".

She praised that twist as the film's "boldest decision... [which robs] the audience of an outcome we are expecting in a way that nobody sees coming", as well as calling the "film-within-a-film structure ... a neat device".

[22] Geoffrey Macnab of the Independent wrote that "Some of the in-jokes begin to grate" but called Arterton's performance "well-judged and engaging" and noted the "scene-stealing antics" of Nighy, Lacy and Irons, particularly lauding Hilliard's shift from "comic buffoon ... [to] depth and pathos".

[23] Robbie Collin of the Telegraph called it a "handsome, rousing, rigorous entertainment you can’t help but play along with" and "Sparklingly adapted", with "bristly chemistry" between the two leads.

He noted Scherfig's direction, with the "broad and rosy spoof" of the film-within-a-film and the gender inequalities of the period left "to squirm away unhindered in the subtext" rather than countered with anachronistic "spiky comebacks".