Ministers who leave Government after rule-breaking would be denied severance pay under Liberal Democrat proposals.
The party is calling for “taxpayer-funded handouts” to “disgraced” former members of government to be scrapped as it enters the third day of annual conference.
Some £530,000 was received in ministerial severance during the last year of political upheaval, according to party analysis of Treasury data.
Ministers are entitled to receive severance payments worth a quarter of their salary on leaving office, provided they are aged under 65 and are not reappointed within three weeks.
But some who received payments last year returned to government within months.
These include Defence Secretary Grant Shapps, who received £16,876 when Liz Truss replaced him as transport secretary at the beginning of September 2022. He returned as home secretary a month later.
He is reported to have given half of his payment to charity.
In a speech to conference, Lib Dem chief whip Wendy Chamberlain will call for a major overall of the payment system.
The proposals would prevent MPs who have resigned for breaking the ministerial code from claiming severance pay.
Ministers would have to serve in post for “a reasonable period of time” and payouts could not be claimed if they are reappointed to government under the party’s plans.
Ms Chamberlain said: “It’s an outrage that while families struggle to pay their bills, Liz Truss, Boris Johnson and other disgraced Conservative ministers have profited from their own failure.
“The cost of Conservative chaos is piling up for families across the country. The British public will never forgive this shambolic Conservative government.
“Conservative ministers crashed the economy and then were rewarded for it. It is time to change the rules over ministerial severance pay for good to end these revolving door payouts – enough is enough.”
Former prime ministers Boris Johnson and Ms Truss both received £18,660 after resigning while Kwasi Kwarteng was given £16,876 when he quit as chancellor after less than six weeks in the job, according to figures released from Government departments.
Among the other ministers to receive severance payments was Chris Pincher, who resigned as deputy chief whip over allegations he groped two men in the Carlton Club, precipitating the crisis that saw Mr Johnson leave office.
Mr Pincher received a £7,920 severance payment after stepping down at the end of June 2022.
Michael Gove also received £16,876 when he was sacked by Mr Johnson as levelling up secretary, a role he has returned to under Rishi Sunak.
A Government spokesperson said there were “longstanding” rules in place to determine how much ministers are entitled to receive on leaving Government and “it is for ministers to decide whether they wish to accept it.”
A Conservative Party spokesman said: “This is exactly the kind of ‘do as I say, not as I do’ policy that the nation expects from the Lib Dems.
“Severance payments have been made by successive administrations over several decades – including at the end of the coalition government in 2015. If their ministers were happy to accept payments then, they should pay them back to British taxpayer before attempting to score political points.”
Ms Chamberlain will speak during the first day of conference on Monday, when delegates will also debate scrapping the Government’s voter ID scheme and new party proposals on housebuilding.
The party has committed to building 150,000 social homes a year – shifting away from a pledge to build 380,000 homes annually in its 2019 manifesto.
But leadership is expected to face opposition from some party members, with a motion put forward by the Young Liberals seeking to insist on the former target.
Related: Caroline Lucas: Green trailblazer who made Westminster listen