Jacob Rees-Mogg’s business partner, a string of Brexit backers and the wife of a former senior minister to Vladimir Putin are among the Conservative donors who have paid more than £7m to socialise with Theresa May since the general election.

Eighty-one party benefactors have paid a total of £7.4m to the Conservative party for access to the prime minister at dinners, lunches after PMQs and drinks receptions since July 2017, records show.

Party insiders said the large amount raised over just nine months from a single revenue stream was evidence that the Tories were aiming to be “election ready” for the autumn.

At least 10 of the donors, who joined the Leader’s Group for £50,000 a head, are supporters of a hard Brexit.

Dominic Johnson, who attended two of the group’s events in 2017, is the co-founder of Somerset Capital Management, an investment firm set up with Rees-Mogg, who chairs the European Research Group of Tory Brexiter MPs.

Somerset was recently reported to be warning its clients about “considerable uncertainty” as a result of Brexit, and set up a fund in Ireland, which benefits from EU financial passporting rights.

Sir Michael Hintze. Photograph: Stuart Clarke/REX

Sir Michael Hintze, the hedge fund billionaire who gave £100,000 to Vote Leave, is a familiar figure in Conservative circles and attended at least one dinner in 2017 with the prime minister, sources said.

Hardy McLain, a retired US hedge fund manager living in London, attended events in 2017 and 2018. He previously donated £20,000 to the Vote Leave campaign.

It is the first time since July 2017 that any details of Leader’s Group dinner guests have emerged. Their identities have been quietly released by the Conservatives this week.

Receiving campaign donations is a routine activity for politicians. But each gift carries with it a potential conflict of interest if the prime minister’s policies appear to benefit those who made the donations.

Edmund Truell, who attended dinners in 2017 and 2018, owns a Swiss-listed private equity business called Disruptive Capital, whose mission statement is to “exploit market uncertainty” to generate returns.

Only two women are among the Leader’s Group donors disclosed in the documents.

Lubov Chernukhin, whose husband, Vladimir, is a former Russian deputy finance minister, was given access to the prime minister between last July and September. She has given £626,500 to the Tories since 2012, including £160,000 to play tennis with Boris Johnson and £30,000 to dine with the defence secretary, Gavin Williamson.

Alisa Swidler, a US philanthropist and friend of Bill Clinton who has given £336,686 to the party, also attended an event with May.

The Conservatives’ chief executive, the mining tycoon Sir Mick Davis, told a meeting of donors in September that the party needed to raise an additional £6m through the parliamentary cycle if it was to win the next general election.

The party spent £18.5m on last year’s snap election, when the Conservatives lost their working majority. Labour spent £11m. Sources told the Guardian the Tories were aiming for a 40% annual increase in the party’s budget – money that would be spent on up to 100 local campaign coordinators.

Records show that Lord Ashcroft, a former Conservative party treasurer who gave millions to the party under William Hague’s leadership but stopped donating during David Cameron’s premiership, appears to be back in the fold and is a member of May’s Leader’s Group. He was joined by the former government adviser and investor in payday loans, Adrian Beecroft.

May appears to bring cabinet members to each event. She was joined by Amber Rudd, then home secretary, and Brandon Lewis, the party chairman, at events between the election and the end of September; Philip Hammond, the chancellor, and Boris Johnson, then foreign secretary, accompanied her to Leader’s Group meetings in the autumn; between January and April this year, May was joined by Johnson, Michael Gove, Liam Fox and four other cabinet ministers.

The Conservatives had not updated details of donors who attended events since July 2017. Cameron pledged to release information about donors after an outcry over the Leader’s Group dinners and whether they were allowing the rich and powerful to buy access to the cabinet.

The documents were spotted this week by campaigners for a second referendum on membership of the EU. Chris Bryant, the MP for Rhondda and supporter of the People’s Vote campaign, said: “People will rightly be angry to see the government listen to Brexit donors in return for donations to the Tory party while denying the British public a vote on their deal.”

