Using calculations based on research by economists at Oxford University, Unlock Democracy have estimated that big party donors are more than 200 times more likely to get a peerage than ordinary party members - and over 20,000 times more likely than your average voter. 
Multi-millionaire investment banker James Lupton, who has donated over £2.5m to the Conservatives since 2009, is the most prominent donor among the new appointments, which also include lobbyists, MPs who were kicked out by the voters in May and unelected political advisers.
David Cameron has said that his aim is to make the House of Lords reflect the party balance in the House of Commons, but because the Liberal Democrats are over-represented compared to their election vote share, these new appointments actually take the Lords further away from that goal. 
Unlock Democracy are calling for David Cameron to stop further appointments until the House of Lords is reformed. The demand for a halt to appointments has united politicians of different political stripes and academic experts on the constitution.
Notes to editors
 Excluding ex-politicians and other “usual suspects”, there were 83 party political appointments to the Lords between 2005 and 2014. 27 went to people who had donated more than £200,000 to their party during this period, while the remaining 56 were not big donors. The 27 donor appointments were made from a pool of 779 big donors during this period, which gives each big donor a probability of 3.5% of being appointed as a Lord. The 56 non-donor appointments were made from a pool of 383,800 party members, giving each party member a probability of 0.01% of being appointed as a Lord. This can also be compared to the numbers on the electoral roll of 44.6m to estimate the probability of an ordinary voter being appointed as a Lord (0.00015%). This calculation follows the argument in Oxford Economics Discussion Paper 744 http://www.economics.ox.ac.uk/materials/papers/13888/paper744.pdf.
 David Cameron would need to appoint 641 new peers to achieve his goal of matching the political balance of the Lords with May’s election result. Assuming no increase in crossbenchers, this would almost double the size of the House of Lords. Cameron would have to appoint 245 new Conservative peers, 176 Labour, 159 Ukip and 48 Greens, along with 13 from minor parties (the SNP, SDLP and Sinn Féin do not accept peerages). Because the Liberal Democrats are currently over-represented in the Lords compared to their vote share, they would not receive any additional Lords.