The head of Poland's ruling party Jaroslaw Kaczynski announced the measures after an opinion poll showed a 12-point drop in support for his right-wing Law and Justice party.
It came after media reported on the bonuses government ministers received last year.
The prime minister at the time, who awarded the bonuses, fuelled the uproar by insisting that the ministers "deserved these bonuses".
Law and Justice won power in 2015 partly by criticising the previous government for what the party said was extravagant spending.
Law and Justice leader Mr Kaczynski said the party has taken note of the public reaction. He also recalled he had previously said that "you don't go into politics for money".
"Clearly, the people remember these words, and this is why they reacted this way to the bonuses and expect a far-going frugality in public life," he said.
He said the money from the bonuses, which ran into tens of thousands of zlotys, would be donated to a Catholic Church charity.
In a further move, the earnings of politicians at all levels of government will be reduced under a planned law Mr Kaczynski said he hoped would take effect before summer.
The announcement comes as Poland's political parties start preparing for local elections in autumn.
Law and Justice spokeswoman Beata Mazurek said the moves are expected to silence criticism levelled by the opposition.
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