Stanley Tucci and up-and-coming actor Fionn Whitehead have been cast alongside Emma Thompson in The Children Act. Deadline first broke news of the project and Thompson’s involvement in August.

Heavyweight UK producer Duncan Kenworthy, whose credits include Notting Hill and Love Actually, will produce the project, based on Ian McEwan’s novel. Notes on a Scandal filmmaker Richard Eyre has been set to direct.

Story sees Thompson play Fiona Maye, an eminent High Court judget in London who is forced to deal with ethically complex cases of family law. The workload puts a heavy personal price on her personal life as her marriage to American professor Jack (played by Tucci) hits breaking point. In a moment of personal crisis, she is asked to rule in a case of a brilliant boy (played by Whitehead) who, three months from his 18th birthday and still legally a child, is refusing the blood transfusion that will save his life.

Glen Basner’s FilmNation handles worldwide rights for the title, which has sold out internationally since it was shopped to buyers in Toronto last month. Deals include UK and Canada (eOne); Germany (Telemunchen), Italy (BIM), Spain (Vertigo), Australia (Roadshow); Japan (Kino); Latin America (Swen) and a host of others.

FilmNation and BBC Films are co-financing with FilmNation’s Basner and Ben Browning exec producing with Joe Oppenhiemer and Beth Pattinson from BBC Films and Charles Moore.

Filming is set to begin in London this month.

Thomspon is repped by Hamilton Hodell in the UK and CAA in the US.

Tucci is repped by Curtis Brown in the UK and CAA and Anonymous Content in the US.

Whitehead, who can next be seen in Christopher Nolan’s Dunkirk, is repped by Curtis Brown.