The number of politicians and their advisers on the UK public payroll now tops 29,000,
BBC research has found.
The figure includes councillors, MPs, peers, MEPs, members of the Scottish Parliament and Welsh and Northern Ireland assemblies and their staff.
Their total cost is estimated at more than £499m for the year 2007/8.
The figures, from Freedom of Information requests for BBC Radio 4's The Political Club, suggests numbers have increased 10-fold in 30 years.
The programme found that the total cost of MPs' and ministers' pay plus their Commons staff, expenses and allowances, policy development grants and "Short payments" to opposition parties stood at £167m in 2007/8.
The total cost for salaries, expenses and payments to the opposition in the Lords was approximately £19.1m.
Equivalent costs for devolved institutions was £19m for the Scottish Parliament, £10.3m for the Welsh Assembly, £13.3m for the Northern Ireland Assembly and £5.4m for the London Mayor and Assembly.
For the UK's 22,737 councillors and their assistants, the bill for pay and allowances was £254.6m.
MEP's salaries cost £4,821,960, the programme found - but the European Parliament would not disclose the bill for their expenses.
Some 73 special advisers to UK government ministers also cost approximately £5.9m.
Mark Wallace, campaigns director of the Taxpayers' Alliance, described the sums involved as "huge".
He added: "This is a vast bill that I think a lot of people will find extremely shocking when they hear about it.
"The fact is people don't mind paying a reasonable amount for good work, but what they do mind is the idea that there is this huge bill that's actually grown very quietly without ever really consulting people."
As part of a practice known as "tithing", all of the main political parties expect their representatives to make contributions to party funds.
For example, Liberal Democrat councillors are expected to donate 10% of their council pay to the party or face being dropped. Labour also imposes a compulsory levy on its representatives.
The Conservatives say they have banned tithing, but Conservative councillors told the programme's presenter, BBC Newsnight's political editor Michael Crick, that there was a moral pressure to contribute to the party.
Concerns have been expressed about the practice, described by Mr Wallace as "extremely dubious" and "effectively state funding of political parties by the back door".
The programme also spoke to Richard Hall, who was a Lib Dem councillor in North Yorkshire until 2008 when he refused to accept the party's 10% tithe.
He said: "I would not stoop to the level of gutter politics to be forced to buy my approval with public money sourced from the taxpayer, it's as simple as that."
Sir Jeremy Beecham, who was chair of Labour's National Executive Committee when the rules were changed, confirmed it was not possible to be an elected representative for the party without giving it money.
He added: "It is expected of Labour public representatives that we should contribute to the party to which we belong and whom we seek to represent and to help secure the support that we need to do our job as Labour party - or it may be Lib Dem or Conservative - representatives."
Lib Dem MP Simon Hughes insisted: "It seems to me entirely reasonable that if you expect to be a public representative of the party you then are asked for a contribution."
A statement by the Conservative Party said: "It is up to each MP to justify their expenses claims to the public and their constituents, and all MPs have a duty to ensure that their arrangements for holding those surgeries are open, transparent and represent value for money for taxpayers.
"Additionally, all claims now have to go through a much more rigorous process of audit and assurance."
* The Political Club is broadcast at 1100 BST on 13 July on BBC Radio 4. You can listen to it online