By Giles Elgood

LONDON (Reuters) - David Cameron was accused on Friday of cronyism that would "embarrass a medieval court" after he rewarded a long list of his political aides and allies with some of Britain's highest honors to mark his resignation as prime minister.

Cameron stepped down last month after he failed to persuade voters to back staying in the European Union in a referendum, and many of those on his "Resignation Honours" list were prominent in the campaign to remain in the bloc.

Outgoing prime ministers can put forward a list of people to receive honors, ranging from peerages and knighthoods to lesser honors such as membership of the Order of the British Empire.

Among the most prominent names on the list are cabinet ministers Michael Fallon, Patrick McLoughlin and David Lidington, all of whom favored remaining in the EU.

George Osborne, who resigned as finance minister after the Brexit referendum, is made a Companion of Honour.

Also honored is Isabel Spearman, a former fashion public relations executive who worked for Cameron's wife Samantha as a stylist and assistant, and Thea Rogers, an adviser credited with smartening up Osborne's public image.

Cameron's former spin doctor, Craig Oliver, was given a knighthood. Three prominent donors to the Conservative Party were also either made lords or knights.

Cameron's list was attacked by opposition politicians and those who had successfully backed leaving the EU, who argued that he was rewarding the failed "Remain" campaign.

Leave.EU, a group that backed Brexit, said Cameron had "used his final 'losers list' to lavish titles and social status on personal friends, party donors and failed Remain campaigners".

Tom Watson, deputy leader of the opposition Labour Party said Theresa May, who succeeded Cameron as prime minister, should have vetoed the list.

"The fact she has allowed this cronyism to go ahead shows that the Tories will always put their own interests first, Watson said.

Tim Farron, leader of the Liberal Democrats, said the list was "so full of cronies it would embarrass a medieval court".

Cameron, who has been on holiday with his family in Corsica, has not commented. Media attention has focused instead on his striking swimming trunks, said to have cost 225 pounds ($300). Downing Street declined to comment.

The list also held some embarrassment for Labour, which appointed a prominent human rights lawyer, Shami Chakrabarti, as a peer in the House of Lords.

Labour leader Jeremy Corbyn said last year he saw no reason to appoint people to the unelected upper house. He had also appointed Chakrabarti to head an inquiry into anti-Semitism in the party, prompting Jewish leaders to say the review could not be seen as independent.

A Labour statement said: "Shami Chakrabarti shares Jeremy's ambition for reform of the House of Lords."

(Additonal reporting by William James; editing by Stephen Addison)