Government departments spent £461,203 on Christmas parties, decorations and cards from 2002 to 2006, according to figures obtained by the Conservatives.
Spending last Christmas across Whitehall was £127,003
The Northern Ireland Office tops the list on £97,129, followed by what is now the Department for Business, Enterprise and Regulatory Reform.
The Conservatives' figures were compiled from parliamentary answers given by ministers.
A government spokesman stressed staff typically paid for their own parties.
He also pointed out the figures covered five years in a large organisation which employs thousands of people.
Spending last Christmas across Whitehall was £127,003.
The figures show £182,000 was spent on Christmas cards between 2002 and 2006, while £260,000 went on parties and £19,000 on festive decorations.
Shadow chief secretary to the Treasury Philip Hammond said: "Many thousands of hard-pressed families who are struggling to make ends meet this Christmas will be angered to read these figures.
"At a time when everyone else has to tighten their belts, it would be good to see government departments setting an example."
The third-biggest Christmas spender was the Department for Transport, on £87,785, with the Department for Culture, Media and Sport next, on £67,732.
The lowest spender was the Scotland Office, on £2,636, followed by the Department for International Development, on £5,050.
The Tories received no reply from the Department for Children, Schools and Families; the department for the Environment, Food and Rural Affairs; the Foreign Office; the department for Universities and Skills; the Home Office, and the Treasury.