Indian opposition leader Arvind Kejriwal released on bail

One of India’s most prominent opposition leaders has been granted bail after spending almost six months in jail for a corruption case he alleged was politically motivated.

On Friday, India’s supreme court ruled that, Arvind Kejriwal, who is the chief minister of Delhi, should be immediately released from jail in Delhi, where he has been held since his arrest in March .

The judges ruled that as his trial was unlikely to be completed for some time, his “prolonged incarceration amounts to unjust deprivation of liberty”.

The arrest of Kejriwal, who was detained alongside other senior members of his Aam Aadmi party (AAP), took place just a few weeks before the beginning of the national elections and sent shock waves across the country.

Kejriwal has been one of the most outspoken critics of the prime minister, Narendra Modi, and his AAP party has grown to be a significant electoral force in recent years, winning regional elections in Delhi and Punjab. His party is part of an alliance with dozens of other opposition parties that was fighting against Modi and his Bharatiya Janata party (BJP) in the election.

The election returned Modi and the BJP to power in June, but with a much reduced majority in coalition with other parties.

Related: Arvind Kejriwal: the Delhi chief minister jailed by Modi’s government

The Central Bureau of Investigation (CBI) has accused Kejriwal and others in his party of corruption and taking $1bn in bribes in an alleged scam involving liquor licensing in Delhi.

Kejriwal denied the allegations, maintaining that his arrest was illegal and the case was a political conspiracy by the government to hinder the opposition before the election, where Modi was seeking a third term in office. The Modi government has denied any involvement in the cases, stating that the CBI acts independently.

The supreme court granted Kejriwal temporary bail in May to allow him to campaign in the election but he had to return to jail in early June.

Friday’s decision to release Kejriwal comes after other senior detained members of AAP were granted bail in the same case. Among them was his former deputy chief minister, Manish Sisodia, who spent more than 18 months behind bars. After the judgment in Kejriwal’s case, Sisodia said: “Today, once again, truth has won in the fight against lies and conspiracies. The locks of the dictator’s prison are broken by the power of truth.”

In a separate judgment, the supreme court justice Ujjal Bhuyan raised questions of the timing and necessity of Kejriwal’s arrest, stating that it had been “unjustified” and that his continued incarceration was “untenable”.

Despite pressure, Kejriwal had refused to step down from his position and had continued to rule the Delhi government from behind bars since March. The new bail conditions set by the supreme court judges do not give him the freedom to return to his duties as chief minister as normal, preventing him from going to the government secretariat, holding meeting with officials or signing certain documents.

Kejriwal left Tihar jail on Friday and pledged to continue fighting the “anti-national forces working to weaken our country”. It is likely to provide a boost to the AAP, which will be fighting in forthcoming state elections in Haryana and to keep power in the Delhi elections early next year.