Here is The Guardian:
While one doubts whether Baroness Thatcher would wholeheartedly approve of any large screen biopic, it seems likely that she'd have a certain, sneaking affection for The Iron Lady, which prints the legend and keeps the dissent on spartan rations.
The Iron Lady, directed by Phyllida Lloyd from an Abi Morgan script, opts for a breezy, whistle-stop tour through the unstable nitroglycerin of Thatcher's life and times. The tone is jaunty and affectionate, a blend of Yes Minister and The King's Speech, fuelled by flashbacks that bob us back through authorised history.
Yet Streep, it transpires, is the one great weapon of this often silly and suspect picture. Her performance is astonishing and all but flawless; a masterpiece of mimicry which re-imagines Thatcher in all her half-forgotten glory. Streep has the basilisk stare; the tilted, faintly predatory posture. Her delivery, too, is eerily good – a show of demure solicitude, invariably overtaken by steely, wild-eyed stridency.
Two preconceptions about The Iron Lady, the long anticipated film about Margaret Thatcher’s life, are laid to rest on seeing it. The first was that it would be a hatchet job on our former prime minister. Not so: the film is relatively even-handed, and for long stretches sympathetic to its subject.
The second was that it was a travesty for Meryl Streep, the American actress, to be playing such a very English character. Well, those doubts have been assuaged too; Streep is splendid, giving a detailed, authoritative performance that goes way beyond accurate impersonation to evoke Thatcher’s spirit. One can think of a few talented British actresses who might have acquitted themselves well in the role, but it’s hard to imagine them doing it better than Streep.
This is a brave stab at a contemporary life, and even with its flaws it does Margaret Thatcher a certain grudging justice. Awards should be coming Streep’s way; yet her brilliance rather overshadows the film itself.
Check out the trailer here