The group, which campaigns for the creation of an elected second chamber, said that claims in the last parliamentary year showed the Lords was “spiralling out of control both in terms of size and cost”.
According to the research, £1,262,670 has been claimed by peers who had failed to speak in the past year, while £772,719 was claimed in expenses and allowances in the year by the 30 peers who failed to speak during the whole of the last Parliament.
The figures, which have been published as parliament returns from its summer recess, also found 116 peers had to speak since the start of the 2014 Parliamentary session, but had claimed £830,418.
With 45 new peers being created in the dissolution honours list for the last parliament, ERS chief executive Katie Ghose said there was an urgent need to fix address the situation before it gets worse.
“These figures show that the House of Lords is well and truly bust,” she said. “That peers who failed to speak in the chamber during the whole of the last Parliamentary session claimed three quarters of a million pounds in expenses and allowances is a damning indictment on the upper chamber.
“Almost £100,000 of that was claimed by peers who voted fewer than five times, while just eight peers claimed £30,000 – despite not voting or speaking at all in the last session. This is a national scandal, and the sooner we sort out this mess the better.”
The fact that peers can claim thousands without even speaking highlighted the lack of accountability for members of the Lords, she added. “The public can’t kick them out if they fail to serve the interests of citizens.
“The prime minister says he regrets not reforming the chamber in the last Parliament. Given these new findings, now is the time to act on that and get on with the vital work of ensuring we have a democratic upper House, where the public finally get a say.”
