Bangladeshi Nobel laureate Muhammad Yunus vowed Sunday to overcome scores of court cases that his supporters say are politically motivated to achieve his environmental and economic policies.

"Our dream is to create a new world," 83-year-old Yunus told reporters outside court, after he was formally granted bail in his appeal against a six-month prison sentence in a case widely criticised by human rights groups.

Yunus is credited with lifting millions out of poverty with his pioneering microfinance bank but has incurred the wrath of Bangladesh's longtime Prime Minister Sheikh Hasina, who has accused him of "sucking blood" from the poor.

Hasina, who was sworn in for a fifth term this month after a landslide victory in an election boycotted by the opposition, has made several scathing verbal attacks against the internationally respected 2006 Nobel Peace Prize winner.

His conviction on January 1 related to labour law violations, but lawyers said Yunus faces at least 170 other cases, including major corruption charges that could see him jailed for years if found guilty.

He denies all wrongdoing.

Yunus, in an emotionally charged speech, said he had dedicated his life to supporting those most in need and was "committed" to continuing his work.

His "Three Zero" plan is aimed to slash carbon emissions, end unemployment and cut poverty.

"We have chased a dream," Yunus said. "We have incurred the annoyance of someone because of chasing this dream," he added, without specifying names.

In the most recent case, Yunus and three colleagues from Grameen Telecom, one of the firms he founded, were accused of violating labour laws when they failed to create a workers' welfare fund in the company.

Yunus alleged the case was brought by a government department, but Minister of Transport Obaidul Quader said the "case was filed by the workers".

Hasina has rejected calls to pardon Yunus and said instead he should seek forgiveness from his employees.