A former governor of Hong Kong, a left-wing rabble-rouser, and an engineer who tackles the nuts and bolts of spectacular inventions that have shaped our world are all speakers at this year's Wells Festival of Literature.

Chris Patten, the last British governor of Hong Kong from 1992 until it was handed back to the Chinese in 1997, kept a diary of his five years there in preparation for the handover.

He has now turned those diaries into a fascinating memoir – he says the politics were a 'snake pit' – which he will discuss with his old friend William Waldegrave at the festival's opening weekend in late October.

Journalist Polly Toynbee, member of a rabble-rousing family of radicals, will explore the myth of mobility and the guilt of privilege which she investigates in her colourful memoir An Uneasy Inheritance. She asks for a truly honest conversation about class in Britain.

On a completely different tack, Roma Agrawal – award-winning engineer and designer of London's famous Shard – deconstructs our most complex feats of engineering into seven fundamental inventions: the nail, spring, wheel, lens, magnet, string and pump.

Other guests that weekend include The Wife of Bath in the person of Marion Turner whose lively biography investigates Chaucer's scandalously colourful character, Labour MP Wes Streeting on his journey from poverty to politics, and theatre director Dominic Dromgoole on a rollercoaster ride through history's theatrical first nights.

These are just a few of the many speakers booked for the festival which runs from 27 October to 4 November, with the full line-up to be announced in the coming weeks.

Priority booking is available in advance to Festival Friends, as is an invitation to a special event on 4 July in which broadcaster and Somerset resident Mariella Frostrup will be in conversation with author Sarah Le Fanu about her career and passion for books.

To become a Friend and for further festival information visit www.wellsfestivalofliterature.org.uk