Jeremy Corbyn will try to revive the memory of Theresa May’s botched election effort today as he visits a key south-east swing seat as part of what Labour sats will be one of its largest ever campaign days.

Corbyn will go to Thurrock as Labour stages a show of force in 420 constituencies across the nation.

The party will concentrate on four policy areas which it says should all involve a message of hope – the future of the NHS; young people; care and dignity for pensioners; and a “fair deal” for workers – in contrast to the Tory u-turns over issues such as the “cruel” dementia tax.

The day continues the upbeat message of Labour conference in Brighton, when Corbyn repeatedly invoked hope in his address while deputy leader Tom Watson said Britons could choose in to live in “love and hope”.

Corbyn’s visit to Thurrock comes after Labour lost the Essex to the Tories by under 600 votes in each of the last three elections.

John McDonnell, the shadow chancellor, will visit Milton Keynes South as shadow cabinet ministers fan out across England, Wales and Scotland.

Corbyn, speaking before Tory conference opens on Sunday, said only Labour offered hope for all of the country .

“Labour is ready. Ready to provide hope for young people held back by lack of opportunity, for pensioners anxious about health and social care, for public servants trying to keep services together and for low and middle earners, the self-employed and employed, facing insecurity and squeezed living standards,” he said.

“The Tories will meet tomorrow in Manchester as a weak and divided party, bereft of ideas and energy, too distracted by the squabbling and plotting in their Cabinet of Chaos to offer any solutions to the momentous issues facing our country.

“Since the election, they have been forced to u-turn over some of their most damaging policies. The cruel dementia tax was scrapped within three days of being announced, their threat to the pensions’ triple lock has been abandoned and their plan to end free school meals in primary schools has been binned.

“Labour is offering hope for the real wealth creators – all of us – and winning the arguments for a new common sense about the direction our country should take, one that transfers wealth, power and opportunity to the many from the few.”