SIX politicians jailed for their part in the independence referendum in Catalonia will leave prison later this month to return to the Catalan Parliament.

Former vice-president Oriol Junqueras, along with former ministers Raul Romeva, Dolors Bassa, Jordi Turull, Josep Rull and Joaquim Forn will give evidence to a commission investigating Spain’s use of Article 155 – the so-called nuclear option – to impose direct rule on Catalonia in autumn 2017.

The commission was established in November 2018 to analyse the effects of the move by then Spanish prime minister Mariano Rajoy.

Catalan penal authorities said they would guarantee the “physical presence” of the prisoners for their “inexcusable duty” in the parliament.

The six are scheduled to appear on January 28 in one of their rare trips outside of prison since November 2017.

Junqueras, Rull, Turull and Romeva were last outside last May after being elected MPs and, in the case of Romeva, senator.

Their appearance follows temporary freedom for Jordi Cuixart, who left Lledoners prison on a 48-hour permit on Thursday night.

READ MORE: Catalan's letter to Lisa Nandy: You've opened the door to police brutality

Jordi Sanchez, who also has a 48-hour permit, is planning to venture out next week.

Prison regulations state that prisoners are eligible for 36 days’ leave every year once they have served a quarter of their sentences.

The two Jordis qualified because they had been in pre-trial detention for two years before being sentenced for sedition.

Meanwhile, Spain’s fledgling government has come into conflict with several judges on the country’s judicial watchdog, a number of whom voted on Thursday against the controversial appointment of a former justice minister as chief prosecutor.

The nomination of Dolores Delgado, who was justice minister until earlier this month, passed by 12 votes to seven, despite sparking accusations of the politicisation of the judiciary.

The General Council of the Judiciary said the seven dissenting members were concerned that the appointment could “create the appearance of a link with the executive branch that does not contribute to the perception of the judiciary’s independence”.

The council is comprised of judges nominated by Prime Minister Pedro Sanchez’s Socialists and the conservative People’s Party.

Sanchez earlier defended his choice for the job: “She is absolutely qualified, has an impeccable resume and a trajectory in the prosecutor’s office that is without question.”

Delgado must now appear before the parliamentary justice committee before the Cabinet votes on her appointment.

A spokesman for the pro-indy Republican Left of Catalonia (ERC), whose support was crucial for Sanchez taking power, said it was too early to criticise the appointment.

Gabriel Rufian told reporters: “We’re hoping for the best and prepared for the worst.”