Rishi Sunak tapped up wealthy Conservative donors to fund an “80:20” campaign at the next election on Thursday night, with a Swarovski crystal-encrusted portrait of the prime minister selling at auction for £25,000. In a speech to guests, the prime minister thanked the room for all “your support of our fantastic party” at the event at the Savoy hotel in London. One attender said guests were given forms that asked them to donate to an “80:20” campaign at the next election, with the party targeting the defence of 80 seats and winning another 20. There were a series of tick boxes up to £10,000, where donors could fill in how much they were willing to give and their details, alongside a message from Sunak. Among those present included Mohamed Mansour, a billionaire businessman and former minister under Egypt’s Hosni Mubarak regime, who is now the party’s senior treasurer. Mansour’s company Unatrac has donated more than £600,000 to the party. Howard Leigh, a donor and former treasurer, is understood to have compered part of the evening. Dominic Raab, the deputy prime minister and justice secretary; Will Quince, a health minister; Mark Harper, the transport secretary; Steve Barclay, the health secretary and Suella Braverman, the home secretary, were among the politicians at the event. Sunak attended with his wife, Akshata Murty, and they left at about 10.30pm. Donors sat on tables with ministers and other party officials, and bought auction prizes including a portrait of Sunak made out of crystals, which sold for £25,000. The picture was made by the London artist San B. Other prizes included a shooting party at Warter Priory in Yorkshire which went for £40,000, and a trip to watch the F1 Abu Dhabi grand prix, which went for £50,000, which was first reported by Guido Fawkes. Asked whether they had attended, one Conservative MP said they had avoided the “distasteful event”. The Conservatives have been struggling to fill their coffers ahead of the next election, with a series of party chairs since Ben Elliot, a businessman and friend of Boris Johnson, left the role in September. Jake Berry was the chair under Liz Truss, followed by Nadhim Zahawi, who resigned over the furore around his tax affairs, and the role in now held by Greg Hands. There have been reports by Bloomberg that the party is facing a shortfall of about £25m ahead of the next election, although the Conservatives insist more donations are coming through. A number of big donors have been reluctant to back the party after the ousting of Johnson. An 80:20 campaign at the next election is likely to be regarded as ambitious given the Conservatives’ position in the opinion polls, with surveys suggesting Labour has a 22- to 28-point lead on the governing party. Sunak’s personal ratings are also struggling against the Labour leader, Keir Starmer.