Spain’s Congress has approved a government reform of the penal code which could benefit Catalan independence leaders but which has triggered a backlash from the opposition and a rebellion among some allies of Prime Minister Pedro Sánchez.

The junior partner in the governing coalition, Unidas Podemos (UP), and the Catalan Republican Left (ERC) were among those that voted alongside Sánchez’s Socialist Workers’ Party (PSOE) to eliminate the crime of sedition and revise down sanctions for the crime of misuse of public funds.

Under the reform, the crime of “aggravated public disorder” replaces sedition which had a maximum term of 15 years.

Meanwhile, sanctions for misuse of public funds have been reduced, but only when the money involved has not been misappropriated for personal gain. The legislation lowers maximum jail sentences in such cases from six years to four.

These changes could benefit several Catalan politicians involved in a failed independence bid in 2017 who have been convicted of sedition and misuse of public funds or who have fled Spain to avoid conviction. Among them is exiled former Catalan President Carles Puigdemont, who has been living in Belgium to avoid extradition.

Another potential beneficiary is ERC leader Oriol Junqueras. Originally banned from public office until 2031, he could run in Catalan elections in 2025, according to the new legislation.

Sánchez had called for both crimes to be reviewed in order to align the Spanish penal code with that of other European countries. However, he has also made clear that the changes are aimed at easing tensions surrounding the Catalan independence issue. On Sunday, he told supporters in Barcelona that the decisions he was taking were “risky” but added that he did not want “Spain and Catalonia to return to the sad and tragic days of 2017.”

Last year, his government pardoned nine Catalan leaders who were jailed for sedition, including Junqueras.

However, that initiative and the changes to the penal code have drawn fierce criticism from the right-wing opposition, which accuses Sánchez of pandering to separatism because his minority administration needs the parliamentary support of the pro-independence ERC.

“All of this is nothing other than a new stop on the road map of the independence movement,” said Cuca Gamarra, of the conservative Popular Party (PP), who added that separatists “are rubbing their hands with glee” at the legislation.

The PP has said that Sánchez is preparing to allow a referendum on Catalan independence, a claim his government rejects.

More worryingly for the prime minister, some senior figures in his own PSOE have also spoken out against the latest reform.

Emiliano García-Page, the Socialist president of the Castille-La Mancha region, said it was “intolerable to negotiate with criminals over their own punishment.”

The reform will now go to the Senate and could be in place by the end of the year.

However, the changes were approved amid an unprecedented situation which saw the PP attempt to block, via judicial appeal, the passage through Congress of a government initiative aimed at easing the appointment of senior judges. Although that was approved, the Constitutional Court is expected to meet Monday to consider the appeal.