Bulgaria's government faces a no-confidence motion next week after thousands of people have been left with water shortages over the past two months, leading to public protests.

The motion, filed by the main opposition Socialists on Monday, comes 10 days after prosecutors charged the then environment minister Neno Dimov with deliberate mismanagement of the water crisis in western Bulgaria, which began in late November and has yet to be resolved. Dimov has since resigned.

This is the fourth attempt by the Socialist Party (BSP) in the last 12 months to topple Prime Minister Boyko Borissov's ruling coalition, although like the previous ones it is likely to fail as the centre-right government has a small majority in parliament.

Bulgaria, a member of the European Union, faces serious environmental challenges, including air pollution from industrial emissions, river pollution and deforestation.

‘I appeal to anyone who wants change, toppling this government and changing the model of government - let's unite because there are topics above us,’ said BSP leader Korneliya Ninova. ‘Clean air, clean water, clean food are topics that can unite us.’

The Socialists, who have 79 seats in the 240-seat parliament, said they had secured the backing of the ethnic-Turkish Movement for Rights and Freedom party but it would still not be enough.

Prosecutors said Dimov, who faces up to eight years in jail if convicted, had failed to take proper measures to avoid a critical draining of a dam that provides drinking water to the town of Pernik, 25 km (16 miles) west of the capital Sofia, and its surrounding villages despite numerous warnings and reports of its decreasing levels.

Nearly 100,000 people have faced water shortages and thousands have joined protests in Pernik in recent weeks over the issue.

Dimov has denied any wrongdoing and blamed the water crisis on dry weather and poor management of the local water facility.

The motion is expected to be voted on next week.