‘Comrades,’ Jim Callaghan told the Labour Party Conference in his first speech as leader in 1976, ‘there is a line of poetry which is a good line for socialists, even if it was not intended to be: “A man’s reach should exceed his grasp/Or what’s a Heaven for?”’ He was quoting Browning’s ‘Andrea del Sarto’. A line of poetry intended to be good for socialists might have been found in Brecht, but Browning would be more familiar, and less alienating, to the wider audience beyond the party.

Margaret Thatcher, in Blackpool in 1987, quoted Kipling’s ‘Recessional’ (‘a humble and contrite heart’), before praising her record in government.

‘Labour’s spin-doctors are trying to convince us they’re doing brilliantly because the NHS is no worse under Labour than it was under the Tories,’ Paddy Ashdown told the Liberal Democrats in Edinburgh in 1999:

It reminds me of a line from the famously bad poet laureate, the McGonagal-like Alfred Austin, who wrote ‘On the Illness of the Prince of Wales’, this immortal couplet: ‘Across the wire the electric message came/He is no better. He is much the same.’

A hundred years earlier, William Harcourt, in his speech to the Liberals in 1897, used Pope’s ‘Universal Prayer’ to pretend to lament the struggles of a rival party:

The poet says, ‘Teach us to feel another’s woes...’ He must be a hard-hearted politician indeed who can view without a feeling of compassion the premature decay of the great Unionist majority.

In 1922, Asquith misquoted Gray’s ‘Progress of Poesy’ to jeer at Lloyd George for getting cold feet about calling a general election:

The kite was vigorously flown with the benediction, if not with the manipulation, of the prime minister’s well-known henchmen in the Press and elsewhere. And after floating for a week or two in what the poet calls the azure deeps of the air, and dominating the whole political horizon, it came down with a heavy bump.

‘A poet wrote, “No man is an island unto himself,”’ Ted Heath reminded the Tories in 1973, a few months after Britain joined the EEC. ‘Today no island is an island. That applies as much to the price of bread as it does to political influence.’

‘Keeping our heads as Labour loses theirs,’ David Cameron said this week, alluding, like Thatcher before him, to Kipling.

In his advice to political speech-makers, Aristotle observes that the logos of a speech (the technical content, the logical argument) isn’t enough; you also have to demonstrate ethos (the credibility and authority of the speaker) and pathos (sharing the values and sentiments of the audience): Browning rather than Brecht, Kipling rather than Geoffrey Hill, Donne rather than Neruda.

Tony Blair, in Brighton in 1997, described Milton as ‘our great poet of renewal and recovery’ before quoting from Areopagitica (not a poem, but never mind): ‘A nation not slow or dull, but of quick, ingenious and piercing spirit, acute to invent, subtle and sinewy to discourse, not beneath the reach of any point that human capacity can soar to.’

It's notable that the poets quoted by party political leaders have almost always not only written in English, but been of English origin: never Scottish, never Welsh. (Gordon Brown misquoted Goethe, without naming him, in 2009: ‘And so I urge you, as the poet said, “dream not small dreams because they cannot change the world.”’)

Jeremy Corbyn’s choice of poets in his inaugural conference speech last week as Labour party leader broke all the rules. He drew on Ben Okri’s 1999 poem ‘Mental Fight’ (its title an allusion to Blake) and Maya Angelou’s foreword to her 2009 Letter to My Daughter (‘You may not control all the events that happen to you, but you can decide not to be reduced by them’). Neither poet is English, although both are from former British colonies, and Angelou is a woman. Celebrated and distinguished female poets, and poets who are not English, have been writing in our language for as long as British party political leaders have been quoting poetry in their speeches. But Corbyn is the first to acknowledge them.