Spain's parliament on Thursday gave the final green light to a contentious amnesty bill for Catalan independentists, paving the way for the return of their figurehead Carles Puigdemont after years of self-exile.

The legislation benefits hundreds of those involved in the failed 2017 Catalan independence bid that triggered Spain's worst political crisis in decades.

The text, which has been strongly opposed by Spain's right and far-right opposition, passed by 177 votes in favor to 172 votes against in the 350-seat parliament. Only one lawmaker was absent from the vote.

Prime Minister Pedro Sanchez hailed the move, saying "forgiveness" was more powerful than holding a grudge over the 2017 crisis.

"In politics, as in life, forgiveness is stronger than resentment," he wrote on X, adding, "Today Spain is more prosperous and more united than in 2017. Coexistence is making progress."

En política, como en la vida, el perdón es más poderoso que el rencor.

Hoy España es más próspera y está más unida que en 2017.

La convivencia se abre camino.

— Pedro Sánchez (@sanchezcastejon) May 30, 2024

The bill was a demand by pro-independence Catalan parties in exchange for their parliamentary support last November, which let him begin a new term in office.

The bill passed its first reading in the lower house in March. It then went to the upper-house Senate, dominated by the right-wing opposition, where it was symbolically vetoed -- the Senate cannot block a bill but only propose amendments -- before returning to the lower house on Thursday morning.

After a heated two-and-a-half-hour debate, during which the Speaker had to restore order multiple times due to exchanged insults, the bill was passed.

The measure, which has dominated Spanish political discourse for months, is estimated by the Justice Ministry to potentially affect around 400 people.

Individual judges will decide if the amnesty applies to specific cases. They have two months to raise issues with the Constitutional Court or the European justice system, which could delay the law's implementation.

Before the vote, right-wing opposition leader Alberto Nunez Feijoo said, "Today, we've witnessed the Socialist Party's death certificate being signed."

His Popular Party (PP) technically won last July's general election but lacked the parliamentary support to form a government, allowing Sanchez to take office with crucial backing from the pro-independence Catalan parties.

In exchange, the Catalan parties demanded the amnesty bill, with its biggest beneficiary being Puigdemont, the former Catalan leader who led the failed independence bid and fled Spain to avoid prosecution.

In an address from Waterloo near Brussels where he lives in self-exile, Puigdemont hailed the passage of the bill as a "historic" day "in the long and unresolved battle between Catalonia and the Spanish state."

"Today we removed the thorns from our feet that prevented us from moving forward," he added.

"Next stop, a referendum," said Gabriel Rufian of the ERC party, referring to the independentists' longstanding demand for a referendum on Catalan independence.

The amnesty has faced strong opposition from the PP and the far-right Vox, which have organized mass street protests against the measure and vowed to continue their fight even after it becomes law.

Surveys indicate Spaniards are divided over the amnesty, including among Sanchez's Socialists and their supporters, though the result of the May 12 Catalan regional election has shifted perceptions.

After a decade in power, the independentists lost their absolute majority, with the Socialists achieving a clear victory, suggesting a shift away from independence.

Despite the Socialists preparing to take over the Catalan government, Puigdemont has expressed his desire to lead a minority pro-independence administration.

He has also expressed hope to return in time to witness the new Catalan government take office, which is scheduled to happen by June 25 at the latest.

However, it remains uncertain if this will be possible given the two-month period allocated for the courts to implement the legislation and cancel outstanding arrest warrants, including Puigdemont's.