Campaigners have demanded reform of the House of Lords after revealing 33 "couch potato peers" who took part in less than a quarter of votes but claimed an average of £14,015 each in tax-free expenses last year.
The peers, who also failed to speak in the chamber, table a written question, or serve on a committee at all in the 2016/17 session, claimed an average of £746 per vote, the Electoral Reform Society (ERS) said.
They made up the total of 72 peers who were "inactive", nearly one in 10 (9.2%) of the total 779, prompting ERS chief executive Darren Hughes to warn the Lords is being treated as a "retirement home".
The report also highlighted that 455 Lords claimed more than the average take home pay of full-time employees despite the Upper House sitting for just 141 days.
The top 300 voting peers accounted for 64% of all votes, while "lobby-fodder lords" rarely deviate from party lines, with 78% of Tories failing to rebel and the average Labour peer opposing the Government in 90% of votes last year.
A large proportion of non-aligned crossbench peers (41%) voted fewer than ten times in 2016/17, compare to 14% for Labour and 7% for Tories.
Mr Hughes also described the Lords as "crony-stuffed" as it hosts 184 ex-MPs, 26 ex-MEPs, 11 ex-MSPs, 8 ex-Welsh AMs, 6 ex-London AMs, 11 ex-MLAs and 39 current or ex-council leaders, as of April 2017.
He said: "Despite some minor reforms, the problems of Britain's broken Upper House continue to fester. With nearly one in ten unelected peers failing to contribute in key ways - despite many of them picking up large sums - we have a democratic crisis in our second chamber.
"The vast majority of party-affiliated peers toe the line, while many crossbench peers simply don't turn up. The so-called 'independent' chamber is packed full of party loyalists.
"The past few years have seen one expenses scandal after another, with peers turning up to claim without substantially contributing. We have seen a barrage of appointments based on patronage. And we've seen peers themselves admit they treat our Upper House as a retirement home, a private members' club. This is no fit state for the mother of all Parliaments.
"This report lays bare the rotten state of this unelected second chamber - from couch-potato peers to lobby-fodder lords. We need real reform now - not tinkering around the edges.
"Politicians must now meet the challenge before this crumbling, crony-stuffed house declines even further. Voters want real change. It's time for both MPs and peers to embrace it."
The ERS obtained data on voting and expenses via the official Lords web pages, and information on spoken contributions from Hansard, the official parliamentary record.
A House of Lords spokesman dismissed the ERS report as a "rehash of publicly available parliamentary data".
The spokesman said: "Their comparison of members' claims to average take home pay is undermined by their inclusion of members' travel costs, which are receipted and are not in any way comparable to a salary.
"It is reasonable that peers can claim allowances to cover the costs they incur when they contribute to the work of Parliament.
"Members can claim £300 or £150 for every day they attend the House and undertake parliamentary work.
"They are expected to pay for any costs associated with attending the House such as their London accommodation and staff costs from this allowance."