The paybill for the Government's special advisers has rocketed by £1 million - an increase of 16%, according to official figures.
The Cabinet Office disclosed the total paid out for advisers to ministers - including "spin doctors" and other political appointees - in 2012-13 was £7.2 million compared with £6.2 million the previous year.
The rise in part reflects an increase in the number of so-called "Spads" working in Whitehall from 85 to 98, despite a promise in the coalition agreement to limit the numbers.
It means the coalition is now spending more on special advisers than the £6.8 million paid out in the last year of the Labour government under Gordon Brown.
Officials said the additional numbers were necessary due to meet the "unusual circumstances" of two-party government.
"Special advisers play an important role in Whitehall, advising ministers and contributing to the smooth running of government," a Cabinet Office spokesman said.
"This is particularly important in a coalition and the number of special advisers reflects the unusual circumstances of this Government - the first coalition government for more than 60 years.
"Research by the IPPR (Institute for Public Policy Research) shows that ministers in Britain receive less support than their counterparts abroad, even compared with countries with Westminster-style democracies.
"The overall number of specials advisers as a proportion of the Senior Civil Service is, and will continue to be, very low - 2.2%."
The figures - slipped out late on a Friday afternoon - show that seven advisers were paid salaries of £100,000 or more.
The two top earners were David Cameron's long-serving chief of staff, Ed Llewellyn, and his communications chief Craig Oliver, who each receive £140,000 - just below the permitted maximum of £142,668.
Christopher Lockwood, who earlier this year joined the No 10 policy unit from The Economist magazine, is next in line with a salary of £134,000. The former journalist is reported to be a close friend of the Prime Minister who once went on holiday with him to Italy.
Mr Cameron's deputy chief of staff Oliver Dowden gets £125,000, his new press secretary Graeme Wilson is on £110,000, and his "gatekeeper" Kate Fall is on £100,000.
Labour MP Phil Wilson said: "David Cameron's promise to put a limit on special advisers is in tatters, with both the number and the cost reaching a record high.
"While he tells the rest of the country to accept cuts, he's happy to spend more and more on his own spin doctors. It's more evidence of how out of touch he is that he thinks the rules don't apply to him.
"As for Nick Clegg's pledge to make sure special advisers are not paid for by the taxpayer - well, we already knew his promises aren't worth the paper they're written on."