Lansdowne Partners is described as "one of Mayfair's largest and most successful hedge funds." It is 20 per cent owned by Morgan Stanley.
Controversies and conflicts of interest
Partner and Conservative Party donor Sir Paul Ruddock disputed this however, claiming the actual amount was only a 'small fraction' of the figure.
In 2013 it emerged that Lansdowne had benefited from investing around £50million in Royal Mail's privatisation, with the value of its shares rising by £18million after one day of trading alone. The Labour Party drew attention to fact that one of Lansdowne's top executives was a close friend of George Osborne. Both the Tories and Lansdowne denied any impropriety, saying Osborne was completely unaware of the share allocations. 
Lansdowne has a 29.2% stake in Circle Holdings PLC, the parent company of Circle Health. The latter has landed £1.36billion worth of NHS contracts, prompting claims of donor influence, given that several of its investors have gifted about £1.5million to the Tories in recent years. Ruddock alone has donated nearly half: £692,592. Sir Martyn Arbib, founder of Invesco Perpetual owns a similar stake 28.7% and has donated around £466,330. 
- Paul Ruddock, co-founding partner. Ruddock is one of the most prominent supporters of the Conservative Party. Up to Feb 2009, he had contributed £260,000 to the party. His donation qualifies him for membership to David Cameron's 100-strong elite donors club, the Leader's Group. He previously worked for Goldman Sachs and Schroders. In 2012 he was awarded a knighthood. 'Sir Paul' denied that this was linked to his donation, but rather for his 'services to arts'.
- Peter Davies, Lansdowne's co-head of developed markets strategy and a member of the hedge fund's management committee. Davies is a close friend of UK Chancellor George Osborne; they met at Oxford University and he was best man at Osborne's wedding in 1998.
Lansdowne's lobbying firm in the UK is Tulchan Communications.
- Hedge Fund thinks bank slide is over, Observer, 1 March 2009
- Steve Swinford, Hedge fund investing in Royal Mail employs George Osborne's friend, The Telegraph, 11 Oct 2013, 10.00pm BST, acc 15 October 2013
- James Lyons, Fury as Tory party donors are handed NHS contracts worth £1.5BILLION under health reforms, Daily Mirror, 8 February 2014, acc 10 Feb 2014