Jeremy Corbyn aims to build on Labour conference by leading a national campaign day this weekend as part of a bid to reclaim a series of key Tory marginals.

Corbyn vowed to take a “message of hope” to key seats tomorrow as tries to send the message that Labour is on the brink of claiming power, following the publication of polling which underlined the party’s recovery over the last year.

He will be joined by a series of senior shadow cabinet ministers with John McDonnell heading to Milton Keynes, home to two targets seats which, according to a leaked briefing published on LabourList, will select candidates before the end of her year.

“Join me in Milton Keynes on Saturday. Together we can win Milton Keynes for Labour at the next General Election,” the shadow chancellor wrote on Twitter.

Both Milton Keynes seats – North and South – are held by the Tories with a majority of fewer than 2,000 votes.

Theresa May kicks off her party’s conference in Manchester this Sunday amid renewed speculation over her leadership and amid claims Philip Hammond was ready to back Boris Johnson as prime minister in the hours after the election result.

In the lull since the end of Labour conference, Corbyn has been aiming to promote key Labour policies on education and the cost of housing. His plan to introduce rent controls triggered an intense debate and prompted an angry reaction on Britain’s right.