Even by her own high standards, Meryl Streep is blindingly good as the British Prime Minister whose name became synonymous with brutally pragmatic market-driven monetarism.
Little wonder: in her fluent Polish in Sophie's Choice; her brittle English refinement in Fred Schepisi's Plenty; her flawless Lindy Chamberlain in Evil Angels; in a host of roles she has accustomed us to performances that blend precise artifice with astonishing dramatic conviction.
When she first appears here - incipiently senile and unrecognised at the corner store - we are amazed at the makeup artists' skills with latex and teeth. But when she speaks, she takes your breath away.
Within minutes she has inhabited the character so completely that she is more real than the real thing. It is an astonishing performance in a career full of them.
The problem is that it's in the service of a very ordinary film. Director Lloyd, a theatre veteran who helmed the film of Mamma Mia, and writer Abi Morgan (the dull adaptation of Monica Ali's Brick Lane), adopt a scenes-from-the-life approach that touches all the bases but lacks a beating heart.